Test Crt And Disk Drives - NCR PC4i Service Manual

BASIC TROUBLESHOOTING
If all memory installed in the computer has been
sucessfully tested,
Drives.
2. Increase the amount of memory indicated by the
configuration switches by minimum increments and
retest by performing the following sequence of
actions:
a. Turn OFF the power.
b. Take out any adapter board which interferes
w i t h
switches.
c. Set the configuration switches to indicate
the next higher increment of memory (see
Chapter 8 for proper switch settings).
d. Replace the adapter board, if removed for
access to the switches.
e. Turn ON the computer again.

TEST CRT AND DISK DRIVES

1. Observe whether any characters and/or the cursor
are displayed on the screen. If they are not, use
either of the diskette-based sets of diagnostic
r o u t i n e s to a t t e m p t
problem.
If the cursor and/or characters (other than a
diagnostic error message) are displayed, go to
Step 2.
2. If a fixed disk drive unit is installed, and
c u r r e n t l y
temporarily disconnected for an earlier test),
listen for the whirring noise that the drive
makes when it is rotating. The drive should be
rotating all the time the processing unit is
turned on.
2-20
go to Test CRT And Disk
access to
a t t a c h e d
the M P B c o n f i g u r a t i o n
i d e n t i f i c a t i o n of the
(it m i g h t h a v e b e e n