Troubleshooting Procedures - Toshiba PORTEGE S100 Maintenance Manual

2.4 System Board Troubleshooting
LED Status
B0h
Check sum check
B1h EC/KBC rewrite check
B2h Start initializing the SC
B6h BIOS rewrite request check
B7h
Rewriting BIOS
PORTEGE S100 Maintenance Manual (960-508)
Table 2-4 D port status (1/8)
Test item
Permission of A20 line and Clearance of software reset
Prohibition of APIC
Initialization for MCH
Initialization for ICH
Initialization for Super I/O
Initialization for Debug port
Dummy read of 3
Setting of printer port
PIT CH0 initialization (for HOLD_ON)
BIOS rewrite flag initialization
Check sum check
EC/KBC rewrite check
Transition to BIOS rewriting when required
When S3 is returned, transaction is transferred to
System BIOS IRT side
Check of Tilde key , Tab key
Start initializing the SC (HLT when LED=B3H or B4H
error occurred)
BIOS rewrite request check
System BIOS rewrite transition to IRT
Initialization for CH.D31
Configuration of DRAM
Permission of cache (only L1 cache)
Memory Clear
Shifting to real mode and cory BIOS on RAM

2 Troubleshooting Procedures

Message
rd
Bus data
Transition to protected mode
Boot block checksum (Skip when S3 is returned)
(HLT when checksum error occurred)
Checksum Except Boot block (Skip when S3 is
returned) (HLT when checksum error occurred)
When key rewriting is requested, go to BIOS rewrite
process
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