Toshiba Tecra M5 Maintenance Manual page 75

2.4 System Board Troubleshooting
Table 2-5 Printer port LED boot mode status (1/9)
LED Status
Permission of A20 and clear of software
reset bit
Prohibition of APIC
Initialization of MCH, ICH
Initialization of Super I/O
Initialization of debug port (For models
supporting debug port)
Dummy read of 3
Setting of printer port (For models
supporting printer port)
B0h PIT CH0 initialization (for HOLD_ON)
BIOS rewrite factor flag initialization
CHECK SUM CHECK
B1h EC/KBC rewrite check
B2h Initialization of SC
Key input (skipped when returned from
S3)
B5h Enables CPU cache
B6h Security check
BIOS rewrite request check
B7h Transits to System BIOS IRT
BIOS rewrite process
Initialization of ICH. D31
DRAM configuration
Permission of cache (L1 cache only)
Memory clear
Transition to real mode and copy of BIOS
to RAM
TECRA M5 Maintenance Manual (960-542)
Test item
rd
Bus data
[CONFIDENTIAL]
2 Troubleshooting Procedures
Contents
Transition to protected mode
Boot block checksum (skipped when
returned from S3)
Halts when error occurs
Checksum other than boot block (skipped
when returned from S3)
If "rewrite" is requested, go to "BIOS rewrite
process".
HLT at LED=B3H or B4, when error occurs
When a key is pressed, check if it is Tilde
key or Tab key. (skipped when returned from
S3)
If Checksum check error occurred on except
Boot Block or rewrite is required by user, go
to "BIOS rewrite process".
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