Zenith Data Systems Z-171 PC Series Service Manual page 77

Page 6-3
System Checkout and Troubleshooting
Table 6-1 (continued): Error Messages
MESSAGE POSSIBLE PROBLEM
+++DISK ERROR: Bad disk controller! +++
+++DISK ERROR: DMA overrun error! +++
These messages usually indicate a malfunction of the disk
controller circuit, but may also appear because of other
defective circuits in the system. If any nonstandard boards
have been installed, they should be suspected first.
+++DISK ERROR: Sector not found! +++
+++DISK ERROR: CRC error! +++
+++DISK ERROR: Invalid address mark detected! + + +
These messages normally indicate that an operating system
was not found on the selected drive disk, or there may
be a faulty drive. First try a different disk. If this error occurs
often, it may be necessary to have the drive aligned or
the disk controller circuit checked.
Set Up
Refer to Chapter 1 for a list of the tools and equipment required for
the following procedure.
1. Disconnect all peripherals from the computer.
2. Remove any circuit boards not supplied by Zenith Data Systems.
3. Verify that power (120 VAC) is available at the power outlet beng
used by the computer.
4. Plug the AC adapter into the computer and then into the pover
outlet.
If no failures are found, a standard computer will not require any disassen -
bly when using the troubleshooting procedure. If a problem is discover:d,
it will be necessary to disassemble the computer to further troubleshoot
the system. Refer to Chapter 4 for the necessary disassembly instructions.