Hello, i am working on a 15 inch color monitor. I have a 150W light bulb connected and when i turn the monitor on, it starts to pulsate for about 10 seconds at 2hz(+-)So it pulsates like 15 to 20 times and then it stays at normal brightness. During all of this the monitor is NOT connected to a PC, but when i do it statrs to pusate again but this time indefenetly. I=B4ve tried changing the refresh rate and this causes the pulses to speed up, so if i go from 800x600/50hz to 800x600/60hz, the pulsating goes from about 1hz to 2hz and if I pull the VGA connector the pulsating stops. Should i try a bigger light bulb? I also get over 1000Vdc (DMM goes blank)both at the chopper transistor=B4s and HOT=B4s drain pin. What controls B+ voltage? is it just the HOT or is there a voltage regulator somewhere? I am looking for a bad V regulatro or maybe a bad resistor somewhere, Am I in the right direction here? Thanks.
18 years ago