I think I broke my CRT

pintris

Newbie
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2CR
hi,

I Have a LG/Philips arcade 31khz CRT monitor. There are two labels on the tube: LG.PHILIPS M46QEF903X21 and Pentranic JVH 19" VGA PF Monitor +TS. It worked fine. It had two "pods" on the main board to adjust H-CEN and ABL.

I was adjusting H-CEN with a small screwdriver and that put the picture more to the center LEFT/RIGHT. Then I tried to adjust ABL but my screwdriver slipped off the pod while turning the pot and i touched "something". It could have been that I touched a GROUND wire which was nearby going around the tube...

The monitor imediately shut down completely. There is a LED on the board which goes from Orange to Green on normal working condition. when I powered the monitor on again that led turned orange and than again shut down.

I waited two hours with the monitor unplugged and tried again. Now I got a little further. The orange led stayed on longer and I hear a "thuck" sound I guess from the hi-power circuit turning on the tube. But after that thuck, the monitor shut down again. I then hear a "crisping" sound (which you usually hear when powering of the monitor)

I waited overnight and tried again but it's the same.

So any ideas what could have happened when I accidently touched something with my small screwdriver? I visually inspected the area around the POT but I don't see anything that looks damaged. I see that there is a cable labeled "ground" going to the tube. Maybe I touched that?

I added 2 images of the board, but it's still mounted in my cabinet...

Many thanks for any help

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gunblade

Active member
vacBacker
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8,735CR
contact rodotron and see if you can get the schematic

its likely a safety resistor or the horizontal output transistor have failed

there is a metal oxide resistor next to that pot, is it actually in the circuit of that pot?
 
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