4-4 Maintenance and Troubleshooting
4.
Turn the mouse over and remove the ball.
5.
Clean the mouse as follows:
n
Clean the mouse ball with tap water and a mild detergent, then dry it with a lint-
free cloth.
n
Remove any dust and lint from the mouse socket.
6.
Replace the mouse ball in its socket.
7.
Replace the ball cover and turn it clockwise until it locks in place.
TROUBLESHOOTING
This subsection provides information that helps isolate and repair system malfunctions at the
field level. Step-by-step instructions for diagnosing and solving system hardware problems are
provided.
If disassembly is required, see Section 5. Connector pin assignments are given in
Appendix A. Jumper settings are given in Appendix B.
Error Messages
Messages may appear when running NEC utilities.
Table Section 4-2
describes possible system
error and warning messages.
Table Section 4-4
describes possible ISA NMI error messages.
Table Section 4-2 PowerMate P System Error Messages
Message
Description
Address Line Short
Error in the address decoding circuitry on the system board.
C: Drive Error
Hard disk drive C not responding. Run Setup (see Section 2, Setup
and Operation) to correct the problem. Also, check C hard disk
drive type in Setup to make sure the hard disk drive type is correct.
C: Drive Failure
Hard disk drive C not responding. Replace the hard disk drive.
Cache Memory Bad, Do Not
Enable Cache
Cache memory is defective.
CH-2 Timer Error
Most AT systems include two timers. There is an error in Timer 2.
CMOS Battery State Low
CMOS RAM is powered by a battery in the RTC/battery backup
chip. The battery power is low. Replace the system board.
CMOS Checksum Failure
After CMOS RAM values are saved, a checksum value is
generated for error checking. The previous value is different from
the current value. Run Setup (see Section 2).
CMOS System Options Not Set
The values stored in CMOS RAM do not match the type detected
by the BIOS. Run Setup (see Section 2).
CMOS Display Type Mismatch
The graphics type in CMOS RAM does not match the type
