Power-On Sequence
At power-on, the flash boot block code initializes the hardware to a known state, then performs basic power-
on diagnostic tests to determine the integrity of the hardware. Initialization performs the following functions:
1.
Initializes CPU and memory controller.
2.
Initializes and configures all PCI devices.
3.
Initializes VGA software.
4.
Initializes the video to a known state.
5.
Initializes USB devices to a known state.
6.
Performs power-on diagnostics. For more information, see “Power-On Diagnostic Tests”.
7.
The unit boots the operating system.
Power-On Diagnostic Tests
The Power-on diagnostics performs basic integrity tests of the hardware to determine its functionality and
configuration. If a diagnostic test fails during hardware initialization the unit simply stops. There are no
messages sent to video.
NOTE:
You may try to restart the unit and run through the diagnostic tests a second time to confirm the first
shutdown.
The following table lists the tests that are performed on the unit.
Test
Description
Boot Block Checksum
Tests boot block code for proper checksum value
DRAM
Simple write/read pattern test of the first 640k of memory
Serial Port
Tests the serial port using simple port verification test to determine if ports are present
Timer
Tests timer interrupt by using polling method
RTC CMOS battery
Tests integrity of RTC CMOS battery
NAND flash device
Tests for proper NAND flash device ID present
Troubleshooting
Basic Troubleshooting
If the computer is experiencing operating problems or will not power on, review the following items.
Table 8-1
Power-On Troubleshooting
Issue
Procedures
The computer unit is experiencing operating
problems.
Ensure that the following connectors are securely plugged into the computer:
Power connector, keyboard, mouse, network RJ-45 connector, monitor
66
Chapter 8 Diagnostics and Troubleshooting
Summary of Contents for mt245
Page 4: ...iv Safety warning notice ...
Page 8: ...viii ...
Page 26: ...18 Chapter 3 Illustrated parts catalog ...
Page 64: ...56 Chapter 5 Removal and replacement procedures for Authorized Service Provider parts ...
Page 70: ...62 Chapter 6 Computer Setup BIOS and MultiBoot ...
Page 72: ...64 Chapter 7 Device management ...
Page 76: ...68 Chapter 8 Diagnostics and Troubleshooting ...
Page 80: ...72 Chapter 10 Adding an Image Restore Tool ...
Page 88: ...80 Chapter 12 Statement of Volatility ...
Page 92: ...84 Chapter 13 Power cord set requirements ...
Page 94: ...86 Chapter 14 Recycling ...
Page 98: ...90 Index ...