IBM 5150 Hardware Maintenance Manual page 20

1. Position the System Unit Power switch to the Off position •
and remove the AC power cord from the wall outlet.
I I
2. Remove all non-IBM devices except the display or optional
cassette player.
3. Turn the Contrast and Brightness controls fully clockwise.
4. See that all connectors are installed securely and in their
proper locations.
Display Power Display Signal
(IBM Display Only) (IBM Display Only)
Keyboard
ARE ALL CONNECTORS INSTALLED SECURELY AND
IN THE PROPER LOCATIONS?
NO
Reconnect or repair the connectors. If this has not
corrected your failure, go to the next page.
YES
010-3