check the H-OUT transistor and any
caps in the power supply near hot spots
that may dry out the caps, disconnect the
h-out transistor before useing youre metre
to check the power supply, then use a light
bolb and connect it to ground and the collector
side of the h-out transistor on the board
with no transistor connected
it should be 120-150volts.
"onyxx" wrote in message
oups.com...
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. Iīve 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
transistorīs and HOTīs 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.
|