Dell 720H2C appendix System Messages, Message Possible Cause Corrective Action

3-2-4	Keyboard Controller Test failure
3-3-1	NVRAM power loss
3-3-2	Invalid NVRAM configuration
3-3-4	Video Memory Test failure
3-4-1	Screen initialization failure
3-4-2	Screen retrace failure
3-4-3	Search for video ROM failure
4-2-1	No timer tick
4-2-2	Shutdown failure
4-2-3	Gate A20 failure
4-2-4	Unexpected interrupt in protected mode
4-3-1	Memory failure above address 0FFFFh
4-3-3	Timer-chip counter 2 failure
4-3-4	Time-of-day clock stopped
4-4-1	Serial or parallel port test failure
4-4-2	Failure to decompress code to shadowed memory
4-4-3	Math-coprocessor test failure
4-4-4	Cache test failure

System Messages

NOTE: If the message you received is not listed in the table, see the documentation for either the operating system or the program that was running when the message appeared.

Message	Possible Cause	Corrective Action
8042 Gate-A20	The keyboard controller	If you receive this message after you make
error	failed its test.	changes in the system setup program,
		enter the system setup program and
		restore the original value(s).
Address Line	An error in the address	Reseat the memory modules (see Memory).
Short!	decoding circuitry in the
	memory has occurred.
C: Drive Error	The hard drive is not	Ensure that the hard drive is installed
	working or is not configured	correctly in the computer (see Hard Drive)
C: Drive	correctly.	and defined correctly in the system setup
		program (see System Setup).
Failure
Cache Memory	The cache memory is not	See Contacting Dell for instructions on
Bad, Do Not	operating.	obtaining technical assistance.
Enable Cache
CH-2 Timer	An error is occurring on the	See Contacting Dell for instructions on
Error	timer on the system board.	obtaining technical assistance.
CMOS Battery	The system configuration	Enter the system setup program (see
State Low	information in the system	Entering System Setup), verify the system
	setup program is incorrect	configuration, and then restart the
CMOS Checksum	or the battery charge may	computer.
	be low.
Failure
CMOS System
Options Not Set
CMOS Display
Type Mismatch
CMOS Memory
Size Mismatch
CMOS Time and
Date Not Set
Diskette Boot	Drive A or B is present but	Ensure that the drive is installed correctly
Failure	has failed the BIOS POST.	in the computer (see Drives) and defined
		correctly in the system setup program (see
		System Setup). Check the interface cable at
		both ends.
DMA Error	Error in the DMA controller	The keyboard or system board may need to
	on the system board.	be replaced.
DMA 1 Error
DMA 2 Error
FDD Controller	The BIOS cannot	Ensure that the floppy drive or the hard