IBM 6151 Maintenance And Service Manual page 365

Step 3
1.
Set the power switch on the system unit to On.
2. Wait about 4 minutes.
3. Try to set the Power On and Brightness Control to the desired
level; then answer the following question.
/
CD
-P-
=
Contrast Control
Power On and Brightness Control
AJZB20A
WERE YOU ABLE TO ADJUST THE BRIGHTNESS
CONTROL TO THE DESIRED LEVEL?
YES Go to "Step 5" on page 3-6200-5.
NO Record SRN 26-620-470, the go to "Step 7" on page 3-6200-7.
(6/88) Problem Isolation Charts
3-6200-3