Toshiba Satellite Pro A120, Maintenance Manual

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2 Troubleshooting Procedures 2.4 System Board Troubleshooting
2-34 [CONFIDENTIAL] TECRA A8 /Satellite Pro A120 Maintenance Manual (960-573)
[ATI chipset model]
Table 2-4-2 Debug port (Boot mode) error status (1/9)
D port status Inspection items Details
Permission of A20 line and clear of
software reset bit
Prohibition of APIC
Initialization of North Bridge and
South Bridge
Initialization of Super I/O
Initialization of debug port
Dummy read of EC 3rd Bus data
Initialization of only PIT CH0
Setting of printer port (only for models
supporting printer port)
CHECK SUM CHECK
Boot block
Transition to Protect mode
Boot block checksum (skip when
returned to S3) (halts, when error) F000
Checksum other than boot block (skip
when returned to S3)
F001 EC/KBC rewrite check If “rewrite” is requested, go to “BIOS rewrite
process”
Initialization of SC When error, holts. DPORT=F003H or F004H F002
Key input (skip when returned to S3) When a key pressed ,check the key (skip when
returned to S3)
F005
Enables CPU cache
Security check F006
BIOS rewrite request check If Checksum check error occurred on except
Boot Block or rewrite is required by user, go to
“BIOS rewrite process”.
Transits to System BIOS IRT
Initialization of South Bridge
Configuration of DRAM
Permission of cache (L1 cache only)
Memory clear
F007
BIOS rewrite process
Transition to real mode and copy of BIOS to
RAM