Test 300 - IBM Personal Computer AT Manual To Operations

Test 400
1
Press Enter
(+-1 )
to start this test.
Did you receive a 4XX error?
XX:XX:XX
ERROR
SYSTEM UNIT 4XX
END - TEST 400
PRESS "ENTER" TO CONTINUE
?
(X
can be any number.)
YES Note the error and have your system unit
serviced. Be sure your Key Lock key is
with your system unit.
NO
If
you do not have an IBM Monochrome
Display attached to your system unit,
press Enter
(+-1)
and refer to the screen
for the next test. Otherwise, go to Step 2.
Test 400-1