IBM 6151 Maintenance And Service Manual page 347

IBM 6153 Advanced Monochrome Graphics Display
PIC 6000
Use this PIC to get an SRN when there is a problem that prevents
you from reading the display screen easily, the two-digit display is
blank, and the power-on indicator is on.
Step 1
Turn the Brightness and Raster Test control fully clockwise until
it clicks into the raster test position.
*
0
t
A.JZB204
IS THE DISPLAY SCREEN COMPLETELY LIGHTED?
NO Go
to
"Step 3" on page 3-6000-3.
YES Continue on the next page.
(6/88) Problem Isolation Charts
3-6000-1