Toshiba M1 manual B5H

2.4 System Board Troubleshooting 2 Troubleshooting Procedures

Table 2-3 Printer port LED boot mode status (2/8)

LED Status	Test item	Message
B5H	Storing key scan code
	Setting of TASK_1ms_TSC
	Display initialization
B6H	FAN control
	Sound controller initialization (for	Enabling system speaker
	beep)
		Disabling mute
		Setting volume to max
	Message display	CEC/KBC UPDATE/DAMAGED, BIOS
		UPDATE/DAMAGED
	Key input	Disabling USB
		Sound beep
		Waiting for key input
	Reading	FDC reset
	CHGBIOSA.EXE/CHGFIRMA.EXE
		Setting of parameter for 2HD (1.44MB), transmission rate
		Reading first sector
		Setting of parameter for 2DD (720KB), transmission rate
		Search of CHGBIOSA.EXE from route directory
		Calculation of directory start head, sector
		Reading contents of route directory by one sector
		Search of entry for "CHGBIOSA.EXE"/
		"CHGFIRMA.EXE", from the sector read
		Reading of EXE header of "CHGBIOSA.EXE"/
		"CHGFIRMA.EXE" key input when an error occurred
		Execute "CHGBIOSA.EXE"/"CHGFIRMA.EXE"
B3H	Prohibition of cache	Prohibition of cache
		Initialization of special register
00H	PIT CH1 initialization	(Setting refresh interval to 30ms)
01H	Check of DRAM type and size	(at Cold Boot)
		(HLT when the DRAM type is 0)
	SM-RAM stack area test	(HLT when the stack area can not be used .)
02H	Cache configuration
	Enabling L1 cache
	CMOS access test	(at Cold Boot) (HLT when an error is detected.)
	Battery level check of CMOS
	CMOS checksum check

TECRA M1 Maintenance Manual (960 -436) 2-21