Zenith Z-100 Series, Reference Manual

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Page 2.3
System Operating Features
Error Messages
Table 2.1 describes possible screen error messages that may occur at powerup
and what you can check to correct the problem. If your action does not resolve
the problem, you will need to have your computer serviced by a qualified indi-
vidual.
Table 2.1. Possible Power-U ostic M s and lan a tions
+++ ERROR: CPU failure!
+++ ERROR: ROM checksum failure!
These two messages indicate that the CPU card may be malfundioning. The
checksum message is a result of a mismatch between a predetermined value
and a value derived from the contents of system ROM. Turn the machine off,
then on again. If the same message reoccurs, you will need to have your system
serviced by a qualiTied individual.
+%+ ERROR: RAM failure! Address: XXXX:YYYY, Bit: N, Chip: UXXX t+t
+++ ERROR: Parity hardware failure! Address: XXXX:YYYY, Bit: N, Chip: UXXX ++I
+++ ERROR: Parity failure! Address: XXXX:YYYY, Chip: UXXX +t+
These messages indicate that the CPU is unable to read or write to the RAM
or video RAM memory. If the chip number displayed is a 400 number, the failure
is on the RAM card. If the chip number is a 300 number, the failure is on the
video card. Before replacing a card, check that the card is properly seated in
the backplane slot and that the CPU DIP switches are correctly set for the amount
of memory installed in the computer.
+4t ERROR: Timer interrupt failure! t+t
This message indicates that the timing logic on the CPU card may have failed.
Make sure that the card is properly seated and set up for the options installed.
Also check that all optional cards are set up correctly.