My beloved PVM1271 tonight decided that after about 1 minute of operation, it was going to shut down. When it does this, it leaves the status LED's on, loses lock on what color system it was decoding, and kills raster as if it was going into HV shutdown. Cycling the power repeats the cycle. There is an interesting slight hum in the audio that doesn't vary with the volume control that alters in pitch with the vertical hold when it does run.

Before I tear into it like a bull in a china shop, I was wondering if anyone here has seen anything like this. I'm hoping it isn't a bad HSTAT divider.

failing electrolytic filter maybe? (judging from the hum)

The hum before it shuts down changes pitch with the vertical hold. There's no other artifacts that point to a power supply issue. If its not the H-stat package, then its got to be a bad cap somewhere.

HVR block! That's the clear plastic box with red potting inside, mounted up on the tube shield with the anode lead coming out the top to the CRT. Try cutting the thin red wire that goes from the board, up to the back of the HVR block, and see if it still shuts down. If not, you can probably get away with just leaving it cut, but know that it may be a little too much high voltage. You will need to replace the HVR block if it's to be done right.

Note: the thin red wire does unplug from the chassis, but it has a safety interlock with a jumper wire in the plug. If you unplug it, it will shut the set down. Hence you must cut the wire, and leave the plug in.

Charles

Thanks Charles. I figured that would be it, since it has almost the same behavior as the old 13" Apple (Sony) Mac monitors.

Is there a preferred source for these?

Are any of these interchangable from one 12" to another?
Could I run the HV down a bit?

Thanks Charles. I figured that would be it, since it has almost the same behavior as the old 13" Apple (Sony) Mac monitors.

Is there a preferred source for these?

Are any of these interchangable from one 12" to another?
Could I run the HV down a bit?

Sony originals would be the best bet. There were a few aftermarket ones, but I don't really trust those. I don't know if there is a possibility of swapping from another set, and I'm afraid usually I don't have luck with Sony "close-but-not-quite" parts swapping. Definitely verify the problem first, as it's always possible that it's something else shutting it down.

Charles