Service manual

Chapter 5 Troubleshooting
63
used, but they will slow down the transfer rate considerably. Please refer to the user
documentation for the device to determine which device you are using.
CAUTION Don't use high voltage differential SCSI devices, they can destroy circuitry on LVD
and SE devices.
18. Disconnect all SCSI devices except the SCSI adapter and the drive at SCSI address 0, and try
again. If this fails, try substituting a known good SCSI adapter and disk drive.
19. Use the Setup Utility to check for resource conflicts, especially if new boards or accessories
have been added.
The SCSI subsystem stops working.
If the SCSI subsystem should stop working, do the following:
1. Review the Troubleshooting Checklist and "Mass Storage Guidelines" in Chapter 2 before
you continue.
2. Run DiagTools. Verify that the SCSI ID and other switch settings are correct and get specific
information or verification that the problem is the SCSI bus.
3. If an accessory board was added recently, check if there is a resource conflict between the new
board and an existing accessory board. Also, if you have changed the options on an existing
board, there may be a resource conflict.
a. Remove the new board and restart the computer. If this corrects the problem, the board is
either defective or it is trying to use a system resource used by the SCSI subsystem.
b. Check if the board is using memory, I/O addresses, or interrupt lines that are also used by
the SCSI subsystem.
4. Check to see if there have been recent changes to any software. For example, has anyone
moved, removed, or changed the configuration files or drivers? Refer to the software
documentation for more information.
5. Check the SCSI cables for problems that may have been caused by recent computer
maintenance, hardware upgrades, or physical damage.
6. If you suspect hardware failure and there are no system error messages, check each
component associated with the failure. Equipment failure is probably the most unlikely reason
for a SCSI subsystem failure.
7. Check the ROM BIOS version associated with the SCSI controller to make sure it is the most
recently issued version.
Video/Monitor Problems
Symptoms:
Nothing is displayed on the monitor.
The monitor is blank and the computer beeps.
The wrong size characters appear on the monitor.
Colors are wrong or there are no colors on the monitor.
If you installed a video board and are not using the built-in video system, go to Step 12.