IBM 5150 Hardware Maintenance Manual page 67

You reached this page because you do not have a properly
functioning Display. You can use an audio response to guide
you. Press the following keys in the sequence listed below.
Listen for the beep each time you press the
~
(Enter) key. /'"'.
Use the numbers on the top row of the keyboard for this test;
do not use the numeric keypad. If you are using cassette
diagnostics, go to page 010-9, complete the instructions on
that page, then return to this page and continue with step 2.
1.
B
Run Diagnostics
2.
~
Enter (Beep)
3.
g
Are the installed devices correct? Yes.
4.
~
Enter(Beep)
rrn
Run Test
5.
U
6.
B
Enter (Beep)
EJ
Enter the number of devices to test.
7.
~
Monochrome Display and Printer Adapter
8.
~
Enter (Beep)(Beep)
WERE YOU ABLE TO COMPLETE THE AUDIO RESPONSE
DIAGNOSTICS BY PRESSING mE ABOVE SEQUENCE
OF KEYS?
NO
You may have a power supply or connector
problem. Check your connector or see PIC 020,
"Power."
YES
400-14