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2-12     NEC Versa 550 Specifications

Battery Charger

The following table lists battery charger specifications.

 Table Section 2-13   Battery Charger Specification

 Input Voltage

 20V (Max.)

 Support Battery

 NiMH Battery (9.6V)

 Protection

 Max. Temp., Max. Timer, Max. Voltage

 Charge Method

 Delta T / Delta t: 1

o

C (min.)

 Max. Temperature

 53

 o

C ~ 56

 o

C

 Timer Setting

 180 Min.

 Charge Time

 Machine On: 3 hours

 Machine Off: 1.5 hours

 Charge IC

 BQ2004

 Operating
Temperature

 10

 o

C ~ 50

 o

C

Keyboard Unit Specification

The following table lists keyboard specifications.

 Table Section 2-14   Keyboard Unit Specification

 Key Switch Type

 Membrane

 Key Stroke

 3.0 

±

 0.5mm

 Operating Force

 50 

±

 20GF

 Key Pitch

 19.05mm

Pointing Device Specification

The following table lists trackball specifications.

 Table Section 2-15   Pointing Device Specification

 Type

 19mm Trackball

 PS/2 Type

Summary of Contents for VERSA 500D WINDOWS 98 - UPGRADE INFORMATION

Page 1: ...ct s discussed in this document are warranted in accordance with the terms of the Warranty Statement accompanying each product However actual performance of each such product is dependent upon factors such as system configuration customer data and operator control Since implementation by customers of each product may vary the suitability of specific product configurations and applications must be ...

Page 2: ...listed including dimensions weight environment safety compliance and power consumption Section 2 NEC Versa 550 Specifications lists system specifications including dimen sions weight environment safety compliance and power consumption Section 3 Hardware Functional Blocks defines major system functions and subsys tems Section 4 Field Service Guidelines provides system disassembly procedures and an ...

Page 3: ...nowledge DC direct current DIP dual in line package DLAB Divisor Latch Address bit DMA direct memory access DMAC DMA controller DOS disk operating system DRAM dynamic RAM DTE data terminal equipment ECC error checking and correction EDS error detecting system EGA Enhanced Graphics Adapter EMS Expanded Memory Specification EPP enhanced parallel port EPROM erasable and programmable ROM EVGA Enhanced...

Page 4: ... Center PAL programmable array logic PC personal computer PCB printed circuit board PFP plastic flat package PIO parallel input output pixel picture element PJQFP plastic J lead quad flat pack PLCC plastic lead chip carrier PLL phase lock loop p p peak to peak PPI programmable peripheral interface PROM programmable ROM QFP quad flat pack RAM random access memory RAMDAC RAM digital to analog RAS ro...

Page 5: ...eceiver transmitter V volt Vdc volts direct current VESA video electronics standards association VFO variable frequency oscillator VGA Video Graphics Array VLSI very large scale integration VRAM virtual RAM W watt µf microfarad µPD microprocessor µs microsecond Ω ohm ...

Page 6: ...rtment 1 10 The Left Side of the Notebook 1 11 Battery Compartment 1 11 PCMCIA Slot Compartment 1 12 DC IN Connector Jack 1 13 Hardware Reset Switch 1 13 The Rear Side of the Notebook 1 13 External Keyboard and PS 2 Mouse Port 1 14 VGA port 1 14 Printer Port LPT 1 1 15 Serial Port COM 1 1 16 The Base of the Computer 1 17 Battery Module Handle and Lock 1 17 Memory Slot Compartment Cover 1 17 System...

Page 7: ...ation 2 8 LCD 2 8 Inverter 2 9 LCD Status Bar Indicator 2 9 FDD Unit Specification 2 10 HDD Unit Specification 2 11 NiMH Battery Pack Specification 2 11 DC DC Converter Specification 2 11 Battery Charger 2 12 Keyboard Unit Specification 2 12 Pointing Device Specification 2 12 Switch Specification 2 13 AC DC Adapter Specification 2 13 BIOS Specification 2 14 Power Management Features Mode Definitio...

Page 8: ...py Disk Drive Subsystem 3 11 Pointing Device Subsystem 3 11 Power Subsystem 3 11 AC Power Adapter 3 11 Internal Battery Pack 3 11 Powerboard 3 12 LCD Inverter Board Assembly 3 12 Section 4 Field Service Guidelines Preventive Maintenance 4 1 Cleaning the Notebook s Exterior 4 1 Cleaning the Notebook s Interior 4 2 Protecting the Disk Drives 4 2 Handling the Computer Battery Packs 4 3 Maintaining th...

Page 9: ... CPU 4 18 Removing Replacing the Entire Motherboard 4 19 Section 5 Troubleshooting and Repair Service Information 5 1 Technical Support 5 2 Product Information 5 2 Ordering Information from FastFacts 5 2 Helpful Questions 5 3 Power On Self Test POST 5 3 POST Messages 5 4 Informational Messages 5 7 Beep Codes 5 7 Explanation of Test Terms for Beep Code Table 5 7 Beep Codes for System Board Errors 5...

Page 10: ...l Port 1 16 1 18 The Base of the Notebook 1 17 1 19 Memory Slot Compartment 1 17 1 20 The Bootup Setting Menu 1 18 1 21 Power Management Setting Menu 1 21 3 1 Functional Block Diagram 3 2 4 1 Removing and Replacing the Trackball Housing Cover 4 4 4 2 NEC Versa 550 Series Illustrated Parts Breakdown 4 7 4 3 Notebook Major Assemblies 4 8 4 4 LCD Assembly 4 9 4 5 System Top Unit Assembly 4 11 4 6 Sys...

Page 11: ...ack Specification 2 11 2 12 DC DC Converter Specification 2 11 2 13 Battery Charger Specification 2 12 2 14 Keyboard Unit Specification 2 12 2 15 Pointing Device Specification 2 12 2 16 Switch Specification 2 13 2 17 AC DC Adapter Specification 2 13 2 18 BIOS Support 2 14 2 19 Power Management Specifications 2 15 2 20 Mode Definitions 2 16 2 21 Mode Action 2 16 2 22 APR Times 2 17 2 23 Hotkey Defi...

Page 12: ...GA Extended Modes Text Mode A 2 A 6 VGA Extended Modes 4 bit Linear Mode A 3 A 7 VGA Extended Modes 8 Bit Linear Mode A 3 A 8 VGA Extended Modes 15 bit Linear Mode A 3 A 9 VGA Extended Modes 16 bit Linear Mode A 3 A 10 VGA Extended Modes 24 bit Linear Mode A 3 A 11 VGA Extended Modes Planar Mode A 4 A 12 VGA Extended Modes Packed Pixel Mode A 4 A 13 VGA High Refresh Modes 8 bit Linear Mode A 4 A 1...

Page 13: ...le computers The NEC Versa 550 Series comes with the following model configurations Table Section 1 1 Model Configurations Configuration Versa 500D 1 Versa 500D 2 Versa 550D CPU Cyrix 486Dx4 75 Cyrix 486DX4 75 Cyrix 5x86 100 On Board DRAM 4 MB 8 MB 8 MB Video Memory 512 KB 1 MB 1 MB Hard Disk Drive 340 MB 340 MB 540 MB Color LCD 9 4 DSTN LCD 9 4 DSTN LCD 10 4 DSTN LCD Battery Pack A 2400mA NiMH A ...

Page 14: ...or external CRT monitor with 256 colors 16 colors for Versa 550D1 HDD Built in 2 5 inch IDE high capacity hard drive 19mm 17mm height FDD Built in 3 5 inch 1 44MB floppy disk drive Keyboard Built in 85 86 key keyboard with 12 programmable function keys embedded numeric keypad and special function control keys dedi cated screen control keys and inverted T cursor keys IBM en hanced 101 102 key compa...

Page 15: ...40x480 DSTN VL Bus Controller VGA Trackball Pointing Device Serial Interface RS 232C Parallel Interface Bank 1 Slot 1 4 8 16MB DIMM Built in HDD PCMCIA Card Slot x 2 PS 2 Keyboard Keyboard PS 2 Mouse RS 232C Peripheral Printer 3 5 FDD Battery Pack External VGA Monitor and PCMCIA Card Figure Section 1 2 System Configuration Diagram ...

Page 16: ...atch Contrast Control Brightness Control Power Indicator Status Panel LCD Panel Power Switch Keyboard Trackball Figure Section 1 3 Front of the Notebook Color LCD Display Panel Both the NEC Versa 500D1 and 500D2 have a built in 9 4 passive matrix dual scan STN DSTN color liquid crystal display LCD that you could adjust and tilt to your desired viewing position The LCD provides 640 x 480 pixels res...

Page 17: ...D hinge is the LCD cover switch button This button automatically depresses and releases when you lower or raise the LCD display panel Depending on your power management settings the button will either switch the notebook to Suspend mode or just shuts off the LCD when you close the LCD panel NOTE If the NEC Versa 550 has been left un used for a prolonged period of time with the AC adapter disconnec...

Page 18: ... icon will start to blink and will generate an intermittent audible beep This warns you to save your data files and connect an AC adapter or swap battery pack This icon informs you that the system is in save to RAM suspend mode when blinking Press any key to resume operation Activates whenever the hard disk drive is being accessed To avoid any data loss never turn off the computer when this icon i...

Page 19: ...ed keyboard with function keys and screen cursor control keys Figure Section 1 5 Standard Keyboard Layout The notebook keyboard is a little bit different from a standard desktop keyboard Aside from the normal alphanumeric characters and the standard keyboard function keys the notebook keyboard includes an embedded numeric keypad and special function keys that activates by pressing the Fn key toget...

Page 20: ...tion Fn key Esc key This key combination puts the system in Suspend mode Fn key F1 key This key combination brings up the Power Management menu Fn key F8 key This key combination toggles between enabling and disabling the battery low warning beep Fn key F10 key This key combination toggles between video display output to the LCD display or to an external CRT monitor Fn key F11 key This key combina...

Page 21: ...retaining latches just above the keyboard panel These latches release the keyboard to give you easy access to the inside of the notebook in performing mainte nance and upgrades Trackball In front of the keyboard panel just right at the center of the palm rest typing surface is the Trackball pointing device The button below and to the left of the trackball is configured by default as the left butto...

Page 22: ...the floppy diskette you press the eject button found on the upper right of the floppy disk drive Hard Disk Drive Compartment Just beside the floppy disk drive is the notebook s internal hard drive The NEC Versa 550 provides industry standard 2 5 inch IDE hard disk drive at 340MB and 540MB The System BIOS of the notebook also includes Auto IDE detection and LBA mode for easy installa tion as well a...

Page 23: ...battery pack from the compartment unit push forward the battery compart ment latch to release lock and slowly pull out the battery pack NOTE There are two types of battery pack for the Versa 550 Series The two Versa 500 models use Type A battery pack swith 2400mA while the NEC Versa 550D model uses Type B battery pack with 2800mA Battery packs are not inter changeable Figure Section 1 10 Removing ...

Page 24: ...find a connector jack where you plug in the AC adapter of the notebook The NEC Versa 550 series provides a universal auto switching AC adapter where you connect the AC power cord and into the power outlet It is important to have the AC adapter connected to the notebook to recharge the battery and keep the notebook working continuously NOTE Use only the AC adapter model that comes with the NEC Vers...

Page 25: ...usly The NEC Versa 550 also provides an optional Y connector adapter allowing simultaneous use of external AT enhanced keyboard and PS 2 mouse When an external PS 2 mouse is connected using the Y connector the built in trackball will automatically be disabled NOTE When connecting an external PS 2 mouse it is required that you power off the computer first before connecting the PS 2 mouse This way t...

Page 26: ...Simultaneous display You need to toggle the display to the external monitor only in order to display higher resolution Refer also to Appendix A for a list of supported video modes Figure Section 1 14 Connecting an External Monitor Printer Port LPT 1 The 25 pin printer port provides a parallel interface to which you can connect a parallel printer or pocket network adapter Many operating systems and...

Page 27: ...mouse After turning on the power again run the BIOS SETUP program and disable the Trackball The Base of the Computer See the following figure for NEC Versa 500 Series bottom features Battery Compartment Latch Battery Pack Handle Memory Compartment Cover Figure Section 1 17 The Base of the Notebook Battery Module Handle and Lock To release the battery module from its compartment push forward the ba...

Page 28: ...As Power On Self Test POST executes during boot up process the screen will display the following message Press Ctrl Alt S to Enter SETUP Press the Ctrl Alt S key combination to run the BIOS Setup program The BIOS Setup program is organized into two pages of menu which you can select using the PgDn and PgUp keys To move from one option to another you use the up and down arrow keys while using the S...

Page 29: ...ng mode which is Enabled automatically for large capacity hard drives over DOS limit of 528MB Hard Disk This option allows you to specify the type of hard drive mounted inside the notebook Always select the Auto 1 option to instruct the BIOS to automatically detect the relevant parameters of the hard drive Some hard drive however do not respond correctly to the values detected In such cases you mu...

Page 30: ... or Bidirectional printer port or to disable the port altogether The default setting is Standard Password This option allows you to limit access to the computer through the use of a password If you select this option a pop up window will appear asking you to set or change the password A password can be up to seven characters in length and is cleared by eliminating the password with the F1 key Note...

Page 31: ...tion allows you to enable or disable power management When this option is Disabled all other power management settings are ignored and disabled as well When set to AC Disabled the power management is disabled only when the computer is powered by the AC adapter HDD Off Timer This option allows you to select a specific time out value after which the hard drive is powered down Possible values include...

Page 32: ...1 20 Technical Information to power up again Set this option to Disable if you want the hard drive to be always spinning ...

Page 33: ...r to the Save to option for more details Auto Power Reduction This option allows you to enable or disable automatic and dynamic microprocessor power reduction during inactivity If enabled the available options reflect an inverse relationship between maximum power savings and maximum performance since the CPU reduces power consumption by clocking down to slower speeds Possible values include Disabl...

Page 34: ...scheduled resume time is determined by the time entered in the Schedule Time option see next item Schedule Time If the Schedule Resume option is Enabled this item allows you to enter a specific time at which the computer automatically exits from sleep or suspend mode The value you enter takes the format hour minute For example an entry of 7 30 will cause the system to exit from sleep or suspend mo...

Page 35: ...d with the MS DOS and Windows 3 1 or higher program 2 Insert the Disk 1 VGA Driver to the floppy disk drive The disk contains the in stallation program called SETUP EXE which provides an easy to install pro cedure in loading the VGA mode drivers to the Windows subdirectory of the hard drive 3 Run the A SETUP EXE command either from the DOS prompt on drive A or from the Windows File Manager This wi...

Page 36: ...e program en ables the system to use a wide range of PC cards that conform to the standards of PCMCIA It support a large number of PCMCIA cards like Flash memory SRAM Mem ory Network LAN ATA hard disks SCSI and other I O cards To install and setup the PCM Plus program quickly 1 Insert the Disk 2 in drive A and type the A INSTALL EXE command at the DOS prompt 2 The Phoenix Card Manager Installation...

Page 37: ...ok diskettes also contains two important system utility program under the PHDISK subdirectory TIME SYS and PHDISK EXE TIME SYS Driver The TIME SYS device driver included with the NEC Versa 550 Series ensures that the system time is properly updated while the system is in suspend mode The TIME SYS driver can be loaded into memory by adding the a device command line to the CONFIG SYS file on the har...

Page 38: ...tition Delete to delete the existing STD partition Info to show detailed information about the STD partition Vram size to override the default video ram size of 1024KB Always reboot the system after you have created or deleted the STD partition so that the NEC Versa 550 s PMU Power Management Unit can establish the correct suspend mode SYSTEM UPGRADES The NEC Versa notebook is easily upgradable to...

Page 39: ...u will find one memory expansion slot 3 Remove the extra SIMM module from its anti static wrapping Make sure that you are properly grounded before handling the memory module Hold the memory module with its connector pointed towards the memory socket Hold the module at 60 degrees see Figure 1 19 and gently connect it to the memory socket by pushing it forward 4 Slowly push the module downwards unti...

Page 40: ...lled FLASH EXE Up date the system BIOS whenever you are upgrading LCD Panel or adding modifications to the computer s hardware function To upgrade the System BIOS 1 Copy the FLASH EXE BIOS utility program and the BIOS ROM file to the hard disk subdirectory You may also choose to run the program from the floppy disk ette 2 Disable EMM386 or other memory manager program before restarting the com put...

Page 41: ...System RAM 4MB 8MB On board Upgradable to 20MB 24MB Memory Module 4MB 8MB 16MB RAM Module Slot One Slot System Management 128Kb Flash BIOS Includes System and VGA BIOS Shadow BIOS Capability Power Management Operation Mode Full Power Mode Doze Mode Sleep Mode 5V Suspend Mode 0 volt Suspend Mode Peripheral Automatic Power Down Cover Switch Support Hard Disk Drive Built in HDD 2 5 inch format 19mm a...

Page 42: ...D CRT Auto Sense Display Output LCD CRT Simultaneous Display Video RAM 512KB 1MB as Standard PCMCIA Slots One Type II or Type III on upper slot and One Type II on lower slot Pointing Device 19mm Trackball Keyboard Keyboard Layout US Layout 85 Keys European Layout 86 Keys Inverted T compatible cursor direction key Overlapped Embedded Function and Numeric Keypad Internal External Keyboard simultaneo...

Page 43: ... FIFO x 1 15 pin VGA Monitor Port x 1 External Keyboard or PS 2 Mouse Port x 1 NEC Y Cable Support DC IN Jack x 1 Status Indicator LCD Status Bar AC In Battery Pack In Battery Low Battery Charge PM Enable 5V Suspend Mode HDD Read Write PCMCIA Card 0 PCMCIA Card 1 FDD Read Write Pad Lock Num Lock Caps Lock Scroll Lock LED Indicator Power On ...

Page 44: ... Battery A 8 long A size 2400mA hr NiMH Battery Cells 9 6V Total 23 04W Battery B 8 long A size 2800mA hr NiMH Battery Cells 9 6V Total 26 88W Battery Life Minimum 2 hours with Cyrix DX4 75 and Battery B option PC Bench Battery Rundown Test Battery Fast Charge Machine On 3 hours maximum Machine Off 1 5 hours maximum Dimension 287mm L x 227mm W x 52 1mm H Weight With Single Battery Pack 2 85kgs w o...

Page 45: ...8JSTT X1 HDD Hitachi 340MB Seagate ST9546 540MB Hitachi DK222A 54 540MB FDD NEC FD1238H YEDATA YD 702J 6037J 01 TEAC FD 05HG 4661 Keyboard Jing Mold 85 86 Keys Pointing Device Logitech 19mm T B Battery Toshiba long A size NiMH battery 2400mA hr and 2800mA hr Core Logic UMC 8486F Video C T 65545 Super I O UMC 82C863 PCMCIA Logic UM8366F UM8365F BIOS Phoenix PMU Keyboard Controller Motorola G10 LapK...

Page 46: ...DSTN LCD Pointing Device 19mm Trackball 19mm Trackball 19mm Trackball MOTHERBOARD The following table lists motherboard specifications Table Section 2 3 Motherboard Specifications Clock Clock Synthesizer AVASEM AV154 04 CPU PGA Socket RAM 1M x 4 bit DRAM x 8 1M x 16 bit DRAM x 4 ROM Flash ROM for BIOS 128K x 8 bit 150ns Video RAM 256K x 16 bit DRAM 5V 70ns SOJ x 1 or 2 System Chipset UMC UM8486F 2...

Page 47: ... Pin FPC Type Straight 1 0mm Pitch SMT To HDD Board 44 Pin Male Straight 2 0mm Pitch DIP To Keyboard 26 Pin FPC Type Straight 2 54mm Pitch DIP To Trackball 6 Pin Male SMT Pitch 1 25mm To Battery Pack 5 Pin DIP To FDD 26 pin FPC Type Straight 1 0mm Pitch SMT External Connector PCMCIA Type II x 2 or Type III x 1and Type II x 1 SMT Double Decks SIO 9 Pin D Sub Male DIP Printer 25 Pin D Sub Female DIP...

Page 48: ...cations Table Section 2 5 Motherboard Cable Specifications HDD 44 Pin Female 2 0mm Pitch Trackball 6 Pin Female 1 25mm Pitch LCD 15 Pin 14 Pin 8 Pin Female 1 25mm Pitch FDD 26 Pin FPC 1 0mm Pitch System Status LCD 26 Pin FPC 1 0mm Pitch DISPLAY UNIT SPECIFICATION The following tables list display unit specifications LCD The LCD panel specifications are listed in the following table Table Section 2...

Page 49: ...rol VR Type Lower VR Type Lower Contrast Control VR Type Upper VR Type Upper Efficiency 70 Min 70 Min Unit Size L x W x H 146 L x 22 5 W x 9 5 H Not available LCD Status Bar Indicator The following table lists LCD status bar indicator specifications Table Section 2 8 LCD Status Bar Indicator Specification Unit Size 85mm L x 16 7mm W x 2 6mm H AC IN battery shaped symbol appears inside when battery...

Page 50: ...MCIA Slot 1 FDD Read Write Pad Lock Num Lock Caps Lock Scroll Lock FDD Unit Specification The following table lists floppy diskette drive specifications Table Section 2 9 FDD Unit Specification Module 3 5 Removable Module Mode 2 Mode FDD for the rest 1 44MB 720KB Unit Size 110mm L x 96mm W x 12 7mm H ...

Page 51: ...ions Table Section 2 11 NiMH Battery Pack Specification Battery Pack A Battery Pack B Capacity 2400 mA x 8 cells 2800 mA x 8 cells Cell Type Long A Long A Voltage 9 6V 9 6V Connector 5 Pin 5 Pin DC DC Converter Specification The following table lists DC DC converter specifications Table Section 2 12 DC DC Converter Specification Input Voltage 8V 20V Output Voltage 12V 5V 3 3V Intel DX4 3 45VV Cyri...

Page 52: ...3 o C 56 o C Timer Setting 180 Min Charge Time Machine On 3 hours Machine Off 1 5 hours Charge IC BQ2004 Operating Temperature 10 o C 50 o C Keyboard Unit Specification The following table lists keyboard specifications Table Section 2 14 Keyboard Unit Specification Key Switch Type Membrane Key Stroke 3 0 0 5mm Operating Force 50 20GF Key Pitch 19 05mm Pointing Device Specification The following ta...

Page 53: ...on Tact Type x 2 pcs Reset Switch Tact Type AC DC Adapter Specification The following table lists AC DC adapter specifications Table Section 2 17 AC DC Adapter Specification Input Voltage AC 90V 265V 47 63Hz Output Voltage 20V Max Protection Short Circuit UVP OVP AC Cord Safety Approval FCC Shielding AC cord DC Output Cable 2 pin 100cm long Indicator AC Power On Unit Size 120mm L x 62mm W x 36mm H...

Page 54: ...llowing features Display to CRT LCD Simultaneous Text Vertical Stretching Graphic Vertical Stretching Maximum Contrast Serial Port Support Standard COM Port Address Parallel Port Support Standard Printer Port Address Shadow Cache Always enable the Shadow for VGA and System BIOS Support CPU L1 Cache with write back function PCMCIA Phoenix PCM Plus provided for supported UMC UM8365F and UM8366F chip...

Page 55: ...ondary Activity for IRQ0 and IRQ8 Timer Interrupted Enabled All Peripherals are in On State Sleep Mode CPU in Divided Frequency State 16MHz Video Display Off by VGA Controller HDD in Sleep Mode Core Logic in Sleep Mode DRAM Slow in Refresh Secondary Activity for IRQ0 and IRQ8 Timer Interrupted Enabled Suspend Mode Enter This Mode via Hot Key Time Out Cover Switch Battery Low Suspend to Memory CPU ...

Page 56: ... Management Features Mode Transition The following tables list mode definitions and actions Table Section 2 20 Mode Definitions H W Mode S W Mode APM Mode User Fully On Full on On CPU Busy On On On CPU Busy Doze Doze Idle Sleep Sleep Standby Suspend 5 0V Suspend Suspend Table Section 2 21 Mode Action Mode CPU Clock Timer APR Fully On Highest Active On 25 MHz 4 seconds Active Doze 16 MHz 4 seconds ...

Page 57: ...lowing table lists hotkey definitions Table Section 2 23 Hotkey Definitions Function Key Content Handler Fn Esc Suspend G10 SMI Fn F10 LCD CRT Display G10 SMI Fn F11 Panel Backlight Off G10 Fn F8 Battery Low Warning Beep G10 SMI Fn F1 Popup Menu G10 SMI Fn PgUp Speaker Volume Increase G10 Fn PgDn Speaker Volume Decrease G10 Fn Num Pad Lock Enable G10 Environmental Specifications The following tabl...

Page 58: ... Axis Vibration Level 5 550 Hz 0 5 Gs Acceleration Duration Time 2 Cycles 60 min for per each axis Non Operating Direction of Movement X Y Z Axis Vibration Level 5 550 Hz 0 04 Inch Displacement Hz 2Gs Acceleration Duration Time 2 Cycles 60 min for per each axis Shock The following table lists shock specifications Table Section 2 27 Shock Specifications Operating Mode Impact Accelerator 10g 11ms Ba...

Page 59: ...NEC Versa 550 Specifications 2 19 ESD The following table lists ESD specifications Table Section 2 28 ESD Specifications Contact Discharge 2 4 6 KV Air Discharge 2 4 8 KV HCP 2 4 6 KV VCP 2 4 6 KV ...

Page 60: ... and LCD Display Panel n I O Subsystem implemented on the Motherboard n Keyboard Subsystem implemented on part of the Motherboard and Keyboard Assembly n PCMCIA Controller and Sockets implemented on the Motherboard n Pointing Device Subsystem implemented on the Motherboard and Keyboard As sembly n Hard Disk Subsystem implemented on the Motherboard and the Hard Drive As sembly n Floppy Disk Subsyst...

Page 61: ...5 CRT ON LCM INVERTER FLASH BIOS 128KB PCMCIA UMC 8365 8366 KB CONTROLLER MOTOROLA G10 SUPER I O UMC UM82C863F TRACKBALL EXT KB MOUSE INTERNAL KB CARD 1 CARD 0 FDD HDD PRINTER CLOCK GEN AVASEM AV9154 04 AC ADAPTER DC DC CONVERTER 14 318MHz 24MHz 66MHz 14 318MHz X TAL BATTERY IN 3 45V 5V 12V DC IN VIDEO RAM 512KB OR 1MB COM1 Figure Section 3 1 Functional Block Diagram ...

Page 62: ...ng system System Processor The System Processor function for the notebook is implemented on the Motherboard using either the 3 45V Cyrix 486DX4 75MHz NEC Versa 500D or the 3 45V Cyrix 5x86 M1sc 100MHz NEC Versa 550D Processor Chip The processor operates in conjunction with RAM and ROM memory and other system control logic e g UMC 8486F to process software instructions BIOS Windows Applications The...

Page 63: ...rnal system board and the processor s internal execution and cache units SYSTEM LOGIC CONTROLLER The System Logic Controller function for the notebook is implemented on the Motherboard using UMC 8486F notebook Chipset The UM8486F is an advanced 486 compatible single chip specially designed for notebook computers and other portable computer Aside from supporting almost all 486 based CPUs the UM8486...

Page 64: ... 64MB by XIP 16MB by EMS Supports Shadow RAM from C0000 FFFFF Supports SLOW and SELF Refresh DRAM Supports Stagger Refresh On board memory up to 48MB Supports Three Memory Banks Supports Page Mode Burst mode operation Supports 512KBx8 1Mx4 1Mx16 2Mx8 and 4Mx4 type DRAM Supports 8 or 16 bit ROM configuration Programmable DRAM timing for each bank n Power Management Supports up to Ten Programmable P...

Page 65: ...SPEND Mode 15uA at POWER OFF Mode with RTC active MEMORY SUBSYSTEM The memory subsystem implemented on the Motherboard includes ROM and DRAM memory Primary control for the memory subsystem is provided by the UMC 8486F System Controller chipset DRAM Memory The NEC Versa 550 notebooks contain 4MB 8MB for NEC Versa 550D1 550D of 70ns page interleaved DRAM on the Motherboard The notebook provides one ...

Page 66: ...rive Electronics type Win chester drives n Hardware or software configuration n Address decoding and strobe generator for game port n Supports two serial port functions n Supports one bi directional IBM PS 2 compatible parallel port function n All functions can be enabled or disabled individually n Configuration Register can be easily selected n Only one 24MHz crystal needed n 100 pin plastic flat...

Page 67: ...grated design flat panel CRT VGA controller RAMDAC clock syn thesizer n Multiple Bus Architecture Integrated Interface Local Bus 32 bit CPU Direct and VL EISA ISA PC AT Bus PCI Bus n Flexible display memory configurations Two 256Kx16 DRAMs 1MB n Integrated programmable linear address feature accelerates GUI performance n Hardware windows acceleration 65545 32 bit graphics engine System to screen a...

Page 68: ...lity to auto sense the display output to both LCD and the external CRT monitor The notebook provides external resolution of 800x600 by 256 colors or 1024x768 by 256 colors for NEC Versa 500D2 550D with 1MB video memory 800x600 by 16 colors or 1024x768 by 16 colors for NEC Versa 500D1 with 512KB memory The 500D2 550D can also provide simultaneous display at 640x480 by 256 colors with the standard V...

Page 69: ... Management Function that includes Individual Socket power control Hot insertion removal Hardware Software controlled power down Modem Ring in Resume CS Controlled Power Down and Power Saving with Windows inactivity n Intel EXCA register compatible n Supports PCMCIA_ATA Specifications n Supports Pulse mode interrupt for I O card n Supports two independent IC card sockets no external buffers needed...

Page 70: ... external PS 2 port also supports the use of an external PS 2 compatible mouse where the system automatically detects on system power up and then disables the internal trackball POWER SUBSYSTEM The Power Subsystem consists of the following major sections n External AC Power Adapter n Internal Battery Pack n Powerboard on Motherboard n LCD Inverter Board in LCD Panel Assembly n Power Conservation L...

Page 71: ... hours maximum when the computer is running Powerboard The Powerboard receives approximately 9 6VDC from the battery pack and uses this input voltage to generate 12V 5V 3 3V 3 45V regulated output voltages to provide power for all internal notebook board assemblies The output of the 5V regulator also drives the LCD inverter circuit on the LCD Inverter Board Assembly Refer to Chapter 2 for more det...

Page 72: ...ent inside the system unit and LCD even after the system is turned off Cleaning the Notebook s Exterior Use the steps below to clean the outer surface of the system 1 Power off the system and remove the primary battery pack Unplug all cables connected to the system 2 Wipe the outside of the system unit keyboard and display with a soft clean cloth Remove stains with a mild liquid detergent like a c...

Page 73: ...dically use a head cleaning diskette in the floppy diskette drive to prolong the life of the drive and to help maintain data integrity Here are some maintenance procedures to use when servicing a hard disk n Always back up the data files from the hard disk n Run a virus detecting program for possible virus infested area on the hard disk n Use SCANDISK to correct any errors found in the directory a...

Page 74: ...s in any way other than as described in this manual and the User s Guide n Always charge the battery packs as soon as possible after a low battery indication Maintaining the LCD Quality When it comes to screen problems heat plays a big part After a good working session the typical routine is to shut the machine and close the cover The display surface no matter what type it is radiates heat When yo...

Page 75: ... Cover REQUIRED TOOLS AND EQUIPMENT All NEC Versa 550 corrective maintenance procedures can be performed using the follow ing tools n Tweezers n Small flat head screwdriver n Small Phillips screwdriver n Small Hex bolt screwdriver NOTE All boards options and peripherals contain components that are sensitive to static electricity When handling any of these items protect against static electricity b...

Page 76: ...92 010A 3 LCD Front Case 10 4 808 875692 009A 4 LCD F Cable 808 875692 024A 5 LCD Panel Kyocera 10 4 808 875599 001A 6 LCD Latch 808 875692 044A 7 Hinge Cover Left 808 875692 006A 8 Hinge Cover Right 808 875692 007A 9 Case Icon LCD Cover 808 875692 005A 10 LCD Status Bar Assembly 808 875692 061A 11 System Top Unit Case Plastic 808 875692 075A 12 U S Keyboard 808 875692 080A 13 Trackball Assembly 8...

Page 77: ...9A 27 Foot Stand 2 808 875692 074A 28 Main Battery 808 875692 002A 29 PCMCIA Cover 808 875692 078A 30 Outer Shipping Carton 808 875692 095A 31 Left Packaging Foam Cushion 808 875692 093A 32 Right Packaging Foam Cushion 808 875692 094A 33 NEC Versa 550 Series User s Guide 808 875692 092A 34 NEC Versa 550 Series Service and Reference Manual this guide 819 200088 000 Rev 00 Not Shown in IPB Figure ...

Page 78: ...Field Service Guidelines 4 7 Figure Section 4 2 NEC Versa 550 Series Illustrated Parts Breakdown ...

Page 79: ...4 8 Field Service Guidelines ...

Page 80: ...g major field replaceable units parts FRUs n LCD Front and Back Panel Cover These parts are used to cover the whole LCD Panel assembly which includes the LCD Display Screen the LCD Power Inverter Board the LCD Cable and the LCD Frame Shielding Plate n LCD Display Screen 9 4 or 10 4 LCD Liquid Crystal Display Screen used for output display This part is assembled together with the LCD Power Inverter...

Page 81: ...CD Cable The LCD cable provides the display signals and voltage connection between the LCD panel and the motherboard There are three sets of wiring cables in side which connects directly to the motherboard one 15 pin one 14 pin and one 8 pin male cable connector Figure Section 4 4 LCD Assembly System Unit Assembly The System Unit Assembly comprise of several sub assemblies of which can be divided ...

Page 82: ...middle part of the unit The LCD Status Bar is con nected to the Motherboard s 26 pin FPC type connector n System Top Unit Cover This part besides the keyboard basically covers the top part of the whole system unit The system top cover also provides a wrist rest surface to where you can rest your wrist while using the keyboard The top unit cover is at tached to the base unit at the sides which snap...

Page 83: ...and follow handling precautions mentioned at the be ginning of this section n Hard Drive Module Assembly The built in hard drive module is attached to the right front side of the system base unit The hard disk module supports 2 5 inch hard disk drive at maximum 19mm height and is secured with four small flat head screws on top of the module The hard drive module is also attached to the system base...

Page 84: ...rts the input 8V 20V DC voltage to several voltage levels needed in powering every components inside the note book This PCB module is located on the left rear side of the base unit and is connected to the Motherboard s 8 pin DIP and 18 pin SMT female connector Figure Section 4 6 System Base Unit Assembly ...

Page 85: ...tion Removing Replacing the Internal Keyboard The procedure for removing and replacing the internal keyboard of the notebook is as fol lows 1 Open the LCD cover to see the keyboard Locate the left and right keyboard latches found on the upper corners of the keyboard just above the key caps 2 Slide the left and right keyboard latches to the left and right respectively Use your finger to tilt the up...

Page 86: ...e screws and the frame lock plate attached secured to the left and right side of the module 4 You will also find there is a ribbon cable connected to the Motherboard s FPC type connector Release the cable by lifting the connector locks at the left and right side using your fingernail or thin pointing object Remove the entire LCD Status Bar assembly from the notebook 5 To remove the LCD Panel from ...

Page 87: ...ll the Trackball cable attached from the top case assembly to the Motherboard Pull the cable out and remove the whole top case assembly 4 The Trackball module is assembled on the system top cover case Turn the top cover case at the back and you will find the trackball printed circuit board Re move the two screws secured to the module and release the trackball assembly 5 To replace the whole top ca...

Page 88: ...LCD panel and the system top cover case and the hard drive module 2 The built in floppy drive module is assembled to the right rear side of the system base unit Release the floppy drive cable connected to the Motherboard s FPC type connector To release the cable from the connector gently lift using your fingernail or thin pointing object the connector locks on the left and right edge 3 Remove the ...

Page 89: ...cedures mentioned from the start of this section 2 The Powerboard is located on the left rear side of the system base unit This part controls the internal power supply of the computer Remove the aluminum strip on top of the powerboard 3 Remove the screw found at the left side of the powerboard Pull out the power board slowly until the left and middle pin connectors have come out of the Moth erboar...

Page 90: ...ed by the CPU to be re leased properly from the system A ventilation duct is near at the back of the CPU to release heat There is also a hole made on the Motherboard right at the bottom of the CPU to release heat easily out of the notebook 3 To remove the CPU you must use a flat blade screwdriver and slowly lift the CPU at every side little by little Also do not pull out the CPU heat sink as it is...

Page 91: ...e of the system base cover casing 4 Take out the whole Motherboard assembly If you want to replace the whole Motherboard with a new one for repair you also have to remove the PCMCIA slots the I O Port Metal Plate Cover and the RTC battery 5 To remove the PCMCIA slot take out the four long screws secured at the back of the Motherboard Make sure not to lose the bolts on top of the PCMCIA slot after ...

Page 92: ...st ROM BIOS 1 508 635 4706 NEC Technical Service Center TSC In the U S call 1 800 632 4525 Listen to the automated attendant and select the appropriate menu to reach one of the following departments Information Center literature dealer locations sales leads response to ads NSRC National Service Response Center questions other than products spare parts or technical support Service Contracts TAC Tec...

Page 93: ... those marked with are for Versa 500D2 and 550D with 1MB video memory VGA STANDARD MODES The following tables list VGA standard modes Table Appendix A 1 VGA Standard Modes Text Mode Hex Mode No of Colors Text Display Font Size Pixel Reso lution Dot Clock MHz Horiz Freq KHz Vert Freq Hz 0 1 16 40 x 25 40 x 25 40 x 25 9 x 16 8 x 14 8 x 8 360 x 400 320 x 350 320 x 200 28 322 25 175 25 175 31 5 70 2 3...

Page 94: ... 175 31 5 70 F Mono 80 x 25 8 x 14 640 x 350 25 175 31 5 70 10 16 80 x 25 8 x 14 640 x 350 25 175 31 5 70 11 2 80 x 30 8 x 16 640 x 480 25 175 31 5 70 12 16 80 x 30 8 x 16 640 x 480 25 175 31 5 70 Table Appendix A 4 Packed Pixel Mode Hex Mode No of Colors Text Display Font Size Pixel Reso lution Dot Clock MHz Horiz Freq KHz Vert Freq Hz 13 256 40 x 25 8 x 8 320 x 200 25 175 31 5 70 VGA EXTENDED MO...

Page 95: ...2 256 100 x 37 8 x 16 800 x 600 40 0 37 5 60 34 256 128 x 48 8 x 16 1024 x 768 65 0 48 5 60 34I 44 9 35 5 43 Table Appendix A 8 VGA Extended Modes 15 bit Linear Mode Hex Mode No of Colors Text Display Font Size Pixel Reso lution Dot Clock MHz Horiz Freq KHz Vert Freq Hz 40 32K 80 x 30 8 x 16 640 x 480 50 350 31 5 60 Table Appendix A 9 VGA Extended Modes 16 bit Linear Mode Hex Mode No of Colors Tex...

Page 96: ...175 31 5 60 7C 256 100 x 37 8 x 16 800 x 600 40 0 37 5 60 7E 256 128 x 48 8 x 16 1024 x 768 65 0 48 5 60 7EI 44 9 35 5 43 VGA HIGH REFRESH MODES The C T 65545 VGA BIOS supports standard high refresh modes listed in the following table Table Appendix A 13 VGA High Refresh Modes 8 bit Linear Mode Hex Mode No of Colors Text Display Font Size Pixel Reso lution Dot Clock MHz Horiz Freq KHz Vert Freq Hz...

Page 97: ... A 15 VGA High Refresh Modes Packed Pixel Mode Hex Mode No of Colors Text Display Font Size Pixel Reso lution Dot Clock MHz Horiz Freq KHz Vert Freq Hz 79 256 80 x 30 8 x 16 640 x 480 31 5 37 5 75 7C 256 100 x 37 8 x 16 800 x 600 49 5 46 9 75 ...

Page 98: ...electronic information service used to obtain up to date product application notes installation procedures troubleshooting tips data sheets techni cal information bulletins price lists and other information Information can be obtained from the FastFacts service 24 hours a day 7 days a week Us ing a touch tone telephone call the FastFacts number order the desired information through the automated a...

Page 99: ...second order before the first order is completed the order could be canceled After three tries FastFacts assumes that the line is busy and will not process the order HELPFUL QUESTIONS Here are some helpful questions to ask when troubleshooting the notebook n Is there any external power source connected to the computer n Is the battery fully charged n Is the computer turned on and the POWER LED act...

Page 100: ...heck the primary video adapter Gate A20 failure The keyboard controller is not accepting command specifically the enable and disable A20 command Check the keyboard controller and system board Turn the power off then back on again If the problem persists contact qualified NEC service personnel Fixed disk configuration error The specified configuration is not supported or doesn t match the actual ha...

Page 101: ...system board Turn the power off then back on again If the problem persists contact qualified service personnel Shutdown failure Either the keyboard controller is not accepting the reset command or the associated reset logic has failed Check the keyboard controller and system board Turn the power off then back on again If the problem persists contact qualified service personnel Time of day not set ...

Page 102: ...rsonnel Keyboard stuck key failure A key is jammed Locate the jammed key and fix it Make sure the keyboard cable and keyboard are connected properly Turn the power off then back on again If the problem persists contact qualified service personnel Memory failure at hex value read hex value expecting hex value Circuitry associated with the memory chips has failed Turn the power off then back on agai...

Page 103: ...y This message indicates that an error was found during POST Pressing the F1 key allows the system to attempt to boot Press F2 allows users to run the ROM based SETUP utility to correct configuration information BEEP CODES Beep codes are used to identify a POST error that occurs when the screen is not available Once the screen is operating diagnostic messages are reported to the screen There are b...

Page 104: ...ded to sum of the ranges will produce a known result such as zero Beep Codes for System Board Errors The following table provides system beep codes Table Section 5 4 BIOS Beep Codes Beep Code Diagnostic Code Description Test Performed none 01h CPU registers test in progress or failure Pattern test of most of the 16 bit CPU registers Failure will result in a system halt 1 1 3 02h CMOS write read te...

Page 105: ...lure results in a system halt 1 4 2 0Dh Parity failure first 64K RAM At the completion of the rolling ones and pattern tests of the first 64K the BIOS checks the parity error bits bits 7 and 6 of port 60h Failure results in a system halt 2 1 1 2 1 2 2 1 3 2 1 4 2 2 1 2 2 2 2 2 3 2 2 4 2 3 1 2 3 2 2 3 3 2 3 4 2 4 1 2 4 2 2 4 3 2 4 4 10h 1Fh First 64K RAM chip or data line failure on bit x The first...

Page 106: ... 3 2 4 27h Keyboard controller test in progress or failure The self test command AAh is issued to the 8042 keyboard controller and the results are monitored Failure results in a system halt None 28h CMOS RAM power failure and checksum calculation test in progress The power fail bit in CMOS RAM is tested and the lower CMOS RAM area is being checksummed A failure does not result in system halt None ...

Page 107: ... 32h Color monitor 40 column operable No specific test is performed just indicates that the BIOS believes a color monitor is installed and is operating The mode has been set to 40 column as selected by the user in CMOS RAM none 33h Color monitor 80 column operable No specific test is performed just indicates that the BIOS believes a color monitor is installed and is operating The mode has been set...

Page 108: ...y above the first 64K is tested with a rolling ones test and a pattern test All success and failure messages are displayed on the screen and POST will continue 4 3 2 3Ah Programmable interval timer channel 2 test in progress or failure Over a period of time the current count values in timer 2 are read and accumulated by ORing them into the values read so far It is expected that during the time per...

Page 109: ...rds installed in the system Memory parity interrupt at address Type S hut off NMI R eboot other keys to continue A memory chip s has failed Check the memory on the system board Unexpected HW interrupt interrupt at address Type R eboot other keys to continue Hardware problem Not displayed if the expected interrupt handler is not enabled Check all hardware in the system Unexpected SW interrupt inter...

Page 110: ...or properly Otherwise replace the powerboard Data on the LCD is unreadable Adjust the brightness and contrast display controls found on the right side of the LCD panel Check if the LCD cables are inserted properly Check also connections inside the LCD panel Check if installed VGA driver is correct Check VGA controller chip on the motherboard if there is any cold or loosed soldering Replace the mot...

Page 111: ...alfunctions Check the connections of all internal devices Replace motherboard Diskette drive does not work Check if floppy drive cable is connected properly Check diskette type if correct and not faulty Replace diskette drive Replace motherboard Hard disk drive malfunction Check if hard disk drive is set properly on CMOS SETUP Check drive cables and connections Check if disk drive is good Replace ...

Page 112: ...kball ring cover and clean the ball and the rollers inside Replace trackball module Check the keyboard controller chip for any cold or loosed soldering Replace the motherboard Serial device does not work If using serial mouse check if trackball option is disabled under CMOS Setup Check if mouse driver is installed properly Check if serial device is connected properly Replace serial device Check th...

Page 113: ...l signal animation The art of making things appear to move in two dimensional 2 D or three dimensional 3 D space and making events happen over time applications programs Software designed to perform specific functions like solving business or mathematical problems audio The range of frequencies that humans hear base RAM Area of system memory between 0 and 640 kilobytes available to the user for op...

Page 114: ...o called baud rate board Printed circuit board Board onto which computer components are soldered and thin wires are printed to connect the components boot To start up a computer See cold boot and warm boot bus An electronic circuit within a computer used for transmitting data or electrical power from one device to another byte Group of eight contiguous bits CD audio Also called digital audio uses ...

Page 115: ...battery that preserves clock calendar data and system con figuration parameters stored in CMOS cold boot Process of starting up the computer by turning on the power If power is already on the process means to turn off the computer and turn it on again A cold boot reinitializes all devices crt Cathode Ray Tube A type of display screen used in desktop monitors It forms the screen image using tiny do...

Page 116: ...igital audio Recorded sounds such as speech and sound effects These are played back by the sound card s Digital to Analog Converter DAC digital sound A description of a sound wave that consists of binary numbers digitizing The process of converting an analog signal into a digital represen tation DSTN Double Scan Super Twisted Nematic A type of technology used in some Versa LCD screen displays enha...

Page 117: ...set of keys on the keyboard usually F1 through F12 that let you get help and error message information or quickly select fre quently used commands hard disk A rigid magnetic storage device that provides fast access to stored data hardware The electrical and mechanical parts from which a computer is made hertz Hz A unit of frequency equal to one cycle per second hot key Combination of two or three ...

Page 118: ...rface A connection that enables two devices to communicate interrupt A special control signal from an I O device that diverts the attention of the microprocessor from the program to a special address kilobyte KB 1024 bytes LAN Local Area Network LCD Liquid Crystal Display An LCD consists of a thin sandwich of two glass plates with sealed edges containing nematic liquid crystal material that forms ...

Page 119: ...ograms or options microprocessor A semiconductor central processing unit that is the principal com ponent of a microcomputer Usually contained on a single chip that includes an arithmetic logic unit control logic and control memory unit MIDI Musical Instrument Digital Interface A standard serial bus digital interface designed to connect electronic musical devices MIDI has no innate sound of its ow...

Page 120: ... by an internal battery The backup battery preserves the clock calendar data and system configuration pa rameters stored in CMOS See volatile memory operating system Set of programs that manage the overall operation of the computer overwrite Storing information at a location where information is already stored thus destroying the original information page A type of message transmission in which a ...

Page 121: ...le de vices Types of PCMCIA cards currently offered by major vendors include fax modems LAN storage cards and wireless communica tions devices peripheral Input or output device not under direct computer control A printer is a peripheral device pixels Picture elements Tiny dots that make up a screen image port Provides the means for an interface between the microprocessor and external devices A cab...

Page 122: ...data is retrieved in a nonsequential manner read To extract data from a storage device such as a diskette ROM Read Only Memory Memory in which stored data cannot be modi fied by the user except under special conditions reset The process of returning a device to zero or to an initial or arbitrarily selected condition resolution The degree of screen image clarity Video display resolution is de termi...

Page 123: ...ation one bit at a time serial printer A printer with a serial interface software Programs that run on a computer such as operating systems word processors and spreadsheets system board The main printed circuit board inside the system unit into which other boards and major chip components such as the system mi croprocessor are connected TFT Thin Film Transistor A type of Versa LCD color screen tha...

Page 124: ... are vola tile memory See nonvolatile memory warm boot Process of resetting the computer without turning off the power through keyboard input pressing Ctrl Alt and Del keys simultane ously or the reset button The system returns to an initial or arbi trarily selected condition waveform A graphic representation of a sound wave as displayed on an os cilloscope which converts sound waves into electron...

Page 125: ...g point unit 3 4 Floppy disk drive 3 11 Function keys 1 7 Functional block diagram 3 2 G Graphics engine 3 8 H Handling battery packs 4 3 Hard disk drive 1 2 Hard disk drive compartment 1 10 Hard disk subsystem 3 10 Hardware reset switch 1 13 Hotkeys 2 17 I I O subsystem 3 7 Integer unit 3 4 Internal battery pack 3 11 K Keyboard 1 2 1 7 Keyboard and mouse port 1 14 Keyboard subsystem 3 9 L LCD ass...

Page 126: ...moving the hard disk drive 4 15 Removing the keyboard 4 13 Removing the motherboard 4 19 Removing the powerboard 4 17 Removing the system top cover 4 15 Removing the trackball assembly 4 15 Replacing the CPU 4 18 ROM 3 7 Run time error messages 5 13 S Serial port 1 16 Service telephone numbers 5 1 Servicing a hard disk 4 2 Servicing the system required tools 4 4 Shock 2 18 Software specification 2...

Page 127: ...Index 3 ...

Page 128: ... However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures n Reorient or relocate the receiving antenna n Increase the separ...

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