4-6
Troubleshooting
Checkpoints
0
A checkpoint is either a byte or word value output to I/O port 80h. The BIOS outputs
checkpoints throughout bootblock and Power-On Self Test (POST) to indicate the task the
system is currently executing. Checkpoint sare very useful in aiding software developers or
technicians in debugging problems that occur during the pre- boot process.
Viewing BIOS checkpoints
0
Viewing all checkpoints generated by the BIOS requires acheckpoint card, also referred to
as a POST card or POST diagnostic card. These are ISA or PCI add-in cards that show the
value of I/O port 80h on a LED display. Checkpoints may appear on the bottom right corner of
the screen during POST. This display method islimited, since it only displays checkpoints that
occur after the video card has been activated.
Bootblock Initialization Code Checkpoints
0
The Bootblock initialization code sets up the chipset, memory, and other components before
system memory is available. The following table describes the type of checkpoints that may
occur during the bootblock initialization portion of the BIOS.
NOTE:
NOTE
:
Please note that checkpoints may differ between different platforms based on system
configuration. Checkpoints may change due to vendor requirements, system chipset or
option ROMs from add-in PCI devices.
Table 4-2.
Checkpoint
Description
Before D0
If boot block debugger is enabled, CPU cache-as-RAM functionality is
enabled at this point. Stack will be enabled from this point.
D0
Early Boot Strap Processor (BSP) initialization like microcode update,
frequency and other CPU critical initialization. Early chipset initialization
is done.
D1
Early super I/O initialization is done including RTC and keyboard
controller. Serial port is
enabled at this point if needed for debugging. NMI is disabled. Perform
keyboard controller BAT test. Save power-on CPUID value in scratch
CMOS. Go to flat mode with 4GB limit and GA20 enabled.
D2
Verify the boot block checksum. System will hang here if checksum is
bad.
D3
Disable CACHE before memory detection. Execute full memory sizing
module. If memory sizing module not executed, start memory refresh and
do memory sizing in Boot block code. Do additional chipset initialization.
Re-enable CACHE. Verify that flat mode is enabled.
D4
Test base 512KB memory. Adjust policies and cache first 8MB. Set
stack.
Summary of Contents for Veriton Z4621G
Page 1: ...Acer VZ4620G VZ4621G SERVICEGUIDE ...
Page 2: ...ii ...
Page 6: ...vi ...
Page 7: ...vii ...
Page 8: ...viii ...
Page 9: ...CHAPTER 1 Hardware Specifications ...
Page 28: ...1 20 Hardware Specifications and Configurations M B Placement 0 ...
Page 30: ...1 22 Hardware Specifications and Configurations Internal header pin definition 0 ...
Page 31: ...Hardware Specifications and Configurations 1 23 Block Diagram 0 ...
Page 32: ...1 24 Hardware Specifications and Configurations ...
Page 33: ...CHAPTER 2 System Utilities ...
Page 50: ...2 18 System Utilities 8 Flash BIOS is finished ...
Page 54: ...2 22 System Utilities 10 Flash BIOS is finished ...
Page 63: ...System Utilities 2 31 12 Select Yes and press Enter key 13 Flash BIOS is finished ...
Page 66: ...2 34 System Utilities 11 Select Yes and press Enter key 12 Flash BIOS is finished ...
Page 69: ...System Utilities 2 37 ...
Page 73: ...System Utilities 2 41 ...
Page 74: ...2 42 System Utilities ...
Page 75: ...CHAPTER 3 System Disassembly and Assembly ...
Page 78: ...3 4 ...
Page 86: ...3 12 System Disassembly and Assembly First open one top side then open the other top side ...
Page 87: ...System Disassembly and Assembly 3 13 Open the low side ...
Page 96: ...3 22 System Disassembly and Assembly Removing the Display Card 0 ...
Page 113: ...System Disassembly and Assembly 3 39 ...
Page 121: ...System Disassembly and Assembly 3 47 Unplug the LCD power cable Take out the LCD with bracket ...
Page 131: ...System Disassembly and Assembly 3 57 Lock all the latch Plug the LVDS cable ...
Page 141: ...System Disassembly and Assembly 3 67 Close the CPU bracket cover ...
Page 147: ...System Disassembly and Assembly 3 73 Lock 2 VGA locks ...
Page 153: ...System Disassembly and Assembly 3 79 Attach the mylar to cover the camera ...
Page 160: ...3 86 System Disassembly and Assembly 4 Attach the mylar as the location shown in the picture ...
Page 164: ...3 90 System Disassembly and Assembly N A 4 Table 3 45 ID Size Quantity Screw Type ...
Page 170: ...3 96 System Disassembly and Assembly Install the hinge cover ...
Page 171: ...System Disassembly and Assembly 3 97 Thermal Pad location on base pan 0 ...
Page 174: ...3 100 System Disassembly and Assembly ...
Page 175: ...CHAPTER 4 Troubleshooting ...
Page 190: ...4 16 Troubleshooting Pressing the 25 calibration points in proper hole by using the stylus ...
Page 194: ...4 20 Troubleshooting ...
Page 195: ...CHAPTER 5 Jumper and Connector Locations ...
Page 196: ...5 2 Jumper Setting 5 4 Setting Jumper 5 4 ...
Page 197: ...Jumper and Connector Locations 5 3 Jumper and Connector Locations ...
Page 200: ...5 6 Jumper and Connector Locations ...
Page 201: ...CHAPTER 6 FRU List ...
Page 202: ...6 2 VZ4620G VZ4621G Exploded Diagrams 6 4 FRU List 6 7 ...
Page 204: ...6 4 FRU Field Replaceable Unit List VZ4620G VZ4621G Exploded Diagrams 0 Main Exploded Diagram ...