background image

CIRCUIT DESCRIPTIONS

PV154 - 923-03506

3-15

ZP26/28 - SERVICING

The Microprocessor uses a combination of I

2

C Bus com-

munication and the Serial Data, Clock and Load lines
for control. The I

2

C communication scheme only requires

2 lines for control. These lines are called SDA and SCL.
Serial Data and Serial Clock respectively.

SRS AUDIO  +29V REGULATOR INDICATED BY D912.

The SRS Audio  +29V supply is generated from pin (8) of
T901. This output is rectified by D910 and filtered by
C915. The choke L912 adds further filtration and C917
removes high frequency switching noise. This supply is
routed to the SRS Audio Output IC IJ01 via the connector
PAQ1 pin 1 and 2.

This voltage is what illuminates the Green Visual Trouble
Shooting LED, D912.

Summary of Contents for R50V26

Page 1: ...2 General Info 1 Service Menu 2 Servicing 3 Part List 4 Diagrams PCB Layouts 5 Schematics 6 Published August 2002 by Technical Publications Zenith Electronics Corporation 201 James Record Road Huntsvi...

Page 2: ...alleled by a 15 mfd 150V AC type capacitor between a known good earth ground water pipe conduit etc and the exposed metallic parts one at a time Measure the AC voltage across the combination of 1500 o...

Page 3: ...lled chemicals These can generate electri cal charge sufficient to damage ES devices 6 Do not remove a replacement ES device from its protective pack age until immediately before you are ready to inst...

Page 4: ...nd the transistor Q403 is on Therefore pin 1 of IC401 receives a voltage causing the hold down circuit to be active This results in the frequency of the hori zontal oscillation and deflection to be st...

Page 5: ...14 MAIN Y PR PB SELECTOR IX04 3 14 SUB Y PR PB SELECTOR IX04 3 14 FRONT AUDIO CONTROL IC IA01 3 14 SRS AUDIO 3 15 TOC 1 SERVICE ADJUSTMENTS 3 16 ZP 25 CHASSIS ADJUSTMENT ORDER 3 16 CHASSIS PRE HEAT RU...

Page 6: ......

Page 7: ...ARRAY V26 MODELS New advanced convergence technology is more accurate than previous digital convergence and is set at the factory by a computer The 9 Point system actually looks at 117 points since it...

Page 8: ...x 26 5 d 226Lbs Finish Light Silver Screen Protector High Contrast Swivel Casters Casters Control Panel Escut Buttons 8 REMOTE CONTROL Transmitter Universal Remote w Glow Channel Vol ume Model Number...

Page 9: ...14 SKIP C S OFF 10 05 AM SLEEP 0 01 STEREO ST SAP TV PG DLSV ANT 1 110 ABC 10 00 AM May 14 2002 C SKIP C S OFF 10 05 AM SLEEP 0 01 TV Normal TV Normal MAIN PICTURE SOURCE CHANNEL LABEL TIME Displays...

Page 10: ...rate picture reproduction Refer to your DVD manual for further information Y P P B R S Video Input 1 and 2 Connections available for some high end equipment that provides even better picture quality R...

Page 11: ...d Tunes back to original channel after 30 60 90 120 150 or 180 seconds FAVORITE CHANNEL Select among 6 different channel classifications QUIT Leaves programming menus and clears screen of displays THU...

Page 12: ...an 216 260 266 282 725 Quasar 259 295 Radio Shack 213 265 730 RCA 216 220 228 240 242 249 260 266 282 283 284 285 286 287 288 708 710 711 725 Realistic 212 213 265 730 Saisho 722 Salora 297 Samsung 22...

Page 13: ...947 MCS 928 Mitsubishi 927 Nakamichi 925 926 Onkyo 923 924 946 Optimus 920 921 922 Panasonic 431 432 945 Phillips 421 433 434 Pioneer 431 435 944 Quasar 432 Radio Shack 431 441 RCA 437 943 Sanyo 438 4...

Page 14: ...e Digit 6 DVD Digit 6 HD STB Digit 6 7 TV Digit 7 VCR Digit 7 Cable Digit 7 DVD Digit 7 HD STB Digit 7 8 TV Digit 8 VCR Digit 8 Cable Digit 8 DVD Digit 8 HD STB Digit 8 9 TV Digit 9 VCR Digit 9 Cable...

Page 15: ...nels Push Select TV Menu Item Select VCR Enter Cable Sat Enter DVD Enter HD STB Enter menu TV Menu VCR Menu Cable Sat Menu DVD Menu HD STB Menu Disc Menu theater TV Theater Modes N A Cable Sat Info DV...

Page 16: ...Del Channel Review Clock Set HD Focus Picture Formats VIDEO SETUP AUDIO THEA TER SEL SPECIAL If certain CATV channels are not received clearly in CATV1 mode set the source to CATV2 mode CHANNEL ADD DE...

Page 17: ...mats Menu Choose and set the options based on your equipment s signal requirements for high definition or standard NTSC sources Aspect Style Normal Wide Zoom or Panorama Vertical Position sets the ima...

Page 18: ...he list Press SELECT to save your choice If you wish to customize your source ID go to Custom and press the RIGHT arrow button Cycle through the character choices using the UP DOWN buttons and cycle t...

Page 19: ...nels or input sources Blocks the signal sent by the equipment such as a VCR connected to the TV Audio Video input jacks Or leave unblocked then choose al lowable ratings Lock the front panel controls...

Page 20: ...t 2 inputs Be sure the TV s internal clock is set before using any Parental Control options Text automatically appears on the screen to indicate if Parental Control Child Lock is activate SECURITY TIM...

Page 21: ...the Special Menu Use the UP DOWN arrow to choose Background Press the RIGHT arrow button to activate the Background option Use the UP DOWN arrow to choose Solid or Shaded Solid Picture is not visible...

Page 22: ...ETUP AUDIO THEA TER SEL SPECIAL PICTURE SETTINGS Press MENU and use the RIGHT LEFT arrow button to access the Audio Menu Use the UP DOWN arrow to choose one of the following options Use the RIGHT LEFT...

Page 23: ...formance SRS and the symbol are trademarks of SRS labs Inc SRS technology is incorporated under license from SRS Labs Inc Licensed by BBE Sound Inc under USP4638258 and 4482866 BBE and the symbol are...

Page 24: ...1 18...

Page 25: ...ircuits and having the associated circuit routes the technician can then Divide and Conquer STAND BY MODE As indicated in the Power On Off circuit diagram expla nation 3 of the 6 shut down inputs are...

Page 26: ...1 the value is shown as a 0 47 ohm however it could be any low ohm value When the current demand increases the voltage drop across the resistor increases If the voltage drop is sufficient to reduce t...

Page 27: ...of these circuits are activated the power supply will STOP and create a Power Supply Shut down Condition SHUT DOWN CIRCUIT DESCRIPTIONS Shut down occurs when pin 1 of Connector PQD2 called PROTECT go...

Page 28: ...condition the high will be impressed on the cathode of DH15 This high is routed to pin 1 of Connector PQD2 called PROTECT and Shut Down occurs as described above 9 Side Pincushion failure generating...

Page 29: ...onnector pin 5 From here the 9V is routed through the Deflection PWB to the Signal PWB via PSD3 connector pin 11 through the coil LC03 to pin 19 of IC01 the Rainforest IC When this voltage is applied...

Page 30: ...P23 Indicating 115V Deflection B is available Colored GREEN 3 DP37 Indicating SW 5V B is available Colored GREEN 4 DP11 Indicating SW 9V B is available Colored GREEN 5 DP35 Indicating 28V B is availab...

Page 31: ...r these conditions H BLK Horizontal and Vertical Blanking is developed within the Deflection circuit The Horizontal Blanking pulse operates around 13V P P and is produced by taking a sample pulse from...

Page 32: ...nd the connector PDF1 pin 1 This is the Dynamic Focus output voltage 28V 26V and RETRACE PULSE 28V and 28V The 28V and the 28V are routed to the Deflection trans former T752 They enter the transformer...

Page 33: ...N09 and applied to the High Volt age Drive IC IH01 at pin 14 When this occurs the IC will stop generating the drive signal that is used to produce High Voltage via QH02 the High Voltage Driver Again t...

Page 34: ...tput Clamp that fixes the DC offset level The DC offset voltage is adjusted by several things When a complete Digital Convergence procedure has been performed and the adjustment information stored in...

Page 35: ...eforms produced within the Hori zontal Deflection circuit or the Vertical Deflection cir cuit The Convergence Yoke assembly manipulates the Beam in accordance with the correction waveforms pro duced b...

Page 36: ...the Serial Data Clock and Load lines for control The I2 C communication scheme only requires 2 lines for control These lines are called SDA and SCL Serial Data and Serial Clock respectively The Micro...

Page 37: ...I2 C bus to the DAC3 IC The output from the Microprocessor is pin 2 SDA1 and 3 SCL1 which arrives at the DAC3 IC at pins 5 and 6 respectively LEVEL SHIFT I004 The Microprocessor operates at 3 3Vdc Mo...

Page 38: ...dy in the Y Pr Pb or Y Cr Cb state will have be converted to this state by I501 The Main Y Pr Pb Selector IC selects the appropriate input between the Tuner AV Inputs S Inputs or Com ponents Communica...

Page 39: ...ed SDA and SCL Serial Data and Serial Clock respectively SRS AUDIO 29V REGULATOR INDICATED BY D912 The SRS Audio 29V supply is generated from pin 8 of T901 This output is rectified by D910 and filtere...

Page 40: ...SC CLEAR 11 Horz Size Adjust Normal Mode NTSC CLEAR 12 Beam Form Normal Mode NTSC 13 Lens Focus Adjust Normal Mode NTSC 14 Static Focus Adjust Normal Mode NTSC 15 Blue Defocus Normal Mode NTSC Color B...

Page 41: ...an example PTSR for RED PTSG for GREEN and PTSB for BLUE 2 Adjust the Focus VR for Red until Focus is achieved A Fine Adjustment will be made later 3 Repeat for Blue and Green DCU CROSSHATCH PHASE AD...

Page 42: ...oke and adjust the TILT until the green is level 2mm tolerance See diagram RED 3 Remove cover or PTS short from RED CRT and align RED with GREEN 1mm tolerance when com pared to Green BLUE 4 Remove cov...

Page 43: ...ring magnet may be moved to facilitate Distance is important not centering ALTERNATE METHOD Adjust Vertical Size until the size matches the chart below ALTERNATE METHOD Adj Vert Size until the size ma...

Page 44: ...PREPARATION Video Control Brightness 90 Contrast Max SCREEN FORMAT should be NORMAL mode ADJUSTMENT PROCEDURE 1 Receive any NTSC crosshatch signal 2 Turn the B FOCUS VR fully clockwise 3 Adjust BLUE d...

Page 45: ...tches the Cen ter of the DCU Crosshatch determined in step 12 19 If center is not correct Repeat steps 12 through 18 until center is matched NOTE To enter the I2 C Bus alignment menu with Power Off pr...

Page 46: ...nt pages until TA1270 M appears at the top of the page 3 Press PIP CH on remote control TA1270 M changes to TA1270 S 4 Observe P852 on the CRT PWB and change the TA1270 S SUB CNT I2 C data so that the...

Page 47: ...36 900 10070 CRT B ASY R 37 895 10143 DEFLECTION YOKE 38 NSP REAR PORT PANEL PLASTIC 39 809 10735 RF BLOCK 40 874 10054 SCREEN PROTECTOR ONLY 901 10023 OP GUIDE 924 10114 REMOTE CONTROL R56W28 LOC PAR...

Page 48: ...C 39 809 10735 RF BLOCK 40 874 10047 SCREEN PROTECTOR ONLY 901 10023 OP GUIDE 924 10114 REMOTE CONTROL R65W28 LOC PART DESCRIPTION 1 NSP MIRROR MOUNT RIGHT 2 NSP MIRROR MOUNT LEFT 3 NSP MIRROR MOUNT U...

Page 49: ......

Page 50: ......

Page 51: ...7 SPEAKER 17 AB NSP BACK CENTER WOOD 18 AB 809 10807 CONTROL PANEL ASY 19 A 814 10234 CABINET LOWER REAR 19 B 814 10236 CABINET LOWER REAR 20 AB 809 10822 VM SUB PCB 21 AB 809 10726 CRX F PACK 22 B 80...

Page 52: ...RILL 17 AB NSP FRONT ACESS COVER WOOD 18 B 849 10057 SPEAKER 18 A 849 10055 SPEAKER 19 AB 809 10726 CRX F PACK 20 AB 809 10836 VM SUB PCB 21 AB 965 10004 CASTER 22 AB 809 10807 CONTROL PANEL ASY 23 AB...

Page 53: ...R ANODE G ANODE B PCV R SCREEN G MAG FERRITE CORE 133 E001 PDF1 MR MAG FERRITE CORE 133 E001 SK BINDER P 3763752 make a loop N001 PQS1 PQD2 PA PQS2 PQD1 PAQ1 POWER SUPPLY P W B POWERCORD THIS DRAWINGA...

Page 54: ...03 PVS1 PCV PZV PVC2 VM P W B PVMS UNIT CONVERGENCE DIGITAL ZP15 CHASS TO R60V26 THIS DRAWINGAPPLIES POWERCORD P W B POWER SUPPLY PAQ1 PQD1 PQS2 PA PQD2 PQS1 N001 make a loop P 3763752 SK BINDER E001...

Page 55: ...l base white Terminal base Red U401 Woofer R VM P W B Woofer L White Red U402 from SIGNAL P W B PZV PCV PVM PVS1 PVS1 EGB1 NCPTB NCPTG PVC1 FOCUS B PZV from SIGNAL P W B from DEFLECTION P W B PFT PFS...

Page 56: ...3 PQD2 PDC1 PFT TUNER 1 TUNER 2 CONVERGENCE P W B PDF2 PCB PDF1 PDK1 PDK3 PR PL PQS1 PZV PZC PCR PDK4 MB PQD1 LX ZCAT2032 0930 E002 E004 PCR PCG ANODE R ANODE G ANODE B PCV R SCREEN G MAG FERRITE CORE...

Page 57: ...W B POWER SUPPLY PAQ1 PQD1 PQS2 PA PQD2 PQS1 N001 make a loop P 3763752 SK BINDER E001 MAG FERRITE CORE 133 MR PDF1 E001 MAG FERRITE CORE 133 SCREEN G R PCV ANODE B ANODE G ANODE R PCG PCR E004 E002...

Page 58: ...R VM P W B Woofer L White Red U402 from SIGNAL P W B PZV PCV PVM PVS1 PVS1 EGB1 NCPTB NCPTG PVC1 FOCUS B PZV from SIGNAL P W B from DEFLECTION P W B PFT PFS from SIGNAL P W B from TERMINAL P W B from...

Page 59: ...ZP26 28 SHEET 1 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFIED Conv...

Page 60: ...8 6 2 ZP26 28 SHEET 2 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFIED...

Page 61: ...7 8 6 3 ZP26 28 SHEET 3 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFI...

Page 62: ...4 ZP26 28 SHEET 4 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFIED Def...

Page 63: ...7 8 6 5 ZP26 28 SHEET 5 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFI...

Page 64: ...8 6 6 ZP26 28 SHEET 6 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFIE...

Page 65: ...7 8 6 7 ZP26 28 SHEET 7 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFI...

Page 66: ...7 8 6 8 ZP26 28 SHEET 8 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFI...

Page 67: ...7 8 6 9 ZP26 28 SHEET 9 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFI...

Page 68: ...8 6 10 ZP26 28 SHEET 10 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIF...

Page 69: ...6 7 8 6 11 ZP26 28 SHEET 11 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SP...

Page 70: ...12 ZP26 28 SHEET 12 NOTE WAVEFORMS AND VOLTAGES WERE MEASURED AT 120VAC CHANNEL 5 AND NSTC COLOR BARS CRITICAL SAFETY COMPONENTS ARE IDENTIFIED BY THE SYMBOL REPLACE ONLY WITH PART NUMBERS SPECIFIED...

Reviews: