VIORE PDP4210EA Service Manual page 106

4. Trouble shooting.
3. Ctrl B/D
CTRL B/D supplies video signal to COF. So if there is a bar defect on screen,
It may be the ctrl b/d problem.
A flow of address signal
In this figure, we can easily suppose
what will be appeared on screen when a specific part failed.
<Diagram of ctrl b/d>
MCM
Buffer
IC
Array저항
각각 16 line
COF IC1 COF IC2
96 output
COF IC3 COF IC4