2.4 System Board Troubleshooting 2 Troubleshooting Procedures
PORTÉGÉ M500 Maintenance Manual (960-559) [CONFIDENTIAL] 2-23
Table 2-4 Debug port (Boot mode) error status (1/10)
D port status Inspection items Details
Permission of A20 and Clear of
software reset bit
Prohibition of APIC
Initialization of MCH and ICH
Initialization of Super I/O
Initialization of debug port
Dummy read of 3rd Bus data
Boot block
Setting of printer port
BTBK_START
Only PIT CH0 initialization
(for HOLD_ON)
BIOS rewrite factor flag initialization
Transition to protected mode
Boot block checksum (skip when returned to S3)
(halts when error)
F000H
CHECK SUM CHECK
Checksum other than boot block (skip when
returned to S3)
BTBK_CALC_CHKSUM_END
EC/KBC rewrite check If “rewrite” is requested, go to “BIOS rewrite
process”
Key input
F001H
When a key is pressed, check if it is
Tilde key or Tab key
BTBK_INI_SC_START F002H
Initialization of SC
F003H BTBK_INI_SC_ERR
F004H BTBK_SC_HW_FAILURE
BTBK_INI_KBC_END F005H
BIOS rewrite request check If Checksum check error occurred on except
Boot Block or rewrite is required by user, go to
“BIOS rewrite process”.
BTBK_ENTER_CHK_BIOS_SIGN F006H
BIOS signature check
BTBK_ENTER_SYSTEM_BIOS
Transits to System BIOS IRT
F007H
BIOS rewrite process Initialization of ICHM. D31