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[Fixed] Another PVM with pincushion failure

NFGx

NFGx

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I've got a 14M4A which recently gave up trying to maintain horizontal restraint, and searching for fixes indicated that yanking L509 would help reveal the nature of the problem.

So I yanked it, into two pieces like what happened to Napoleon IV: https://www.arcade-projects.com/thr...rtion-with-sony-pvm-monitor.20572/post-319551

I'm going to try and solder it back together but I'd love to slap a replacement in there, if only I had any idea what it actually was. (and a friend just found the value: 3,3mmH according to a Trinitron manual, but that's surely 3.3mH) The part number itself seems to be perpetually out of stock.

Does anyone have one going spare?

And does anyone know why there's a third post on the board that doesn't seem to actually connect to the coil itself? The base of the coil was so soft that the third post just pulled through and the base cracked into two pieces around it.
 

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Beating my head against this for a while, trying to make sense of the thread on shmups. After testing the diodes (D502, D506, D512 - shown here) I removed the transistor (Q503) and still had a short somewhere. The next suggestion was C514 - and that was the culprit. As soon as it was removed, the short circuit was gone and things returned to higher resistance as expected. Testing the cap showed it was verifiably shorted.

I'm inclined to test it and see if it works, but I'm not sure that cap is doing heavy work or not, and I really don't need to fry anything else. ^__^; (EDIT - the manual has a ⚠️ next to C514, Sony part 1-130-338-91, because it's 'critical to safety'. So I won't be powering it up without it).

And since the coil in the first post of this thread was broken, I decided to take a gamble and re-wind it. I figure since these things have a large tolerance (most are 20%) losing a few millimetres wouldn't hurt. After unwinding it and getting like four metres of copper thread, I re-wound it as best I could, glued it to the base, and soldered the wires back on the legs. I suspect it will work fine. Fingers crossed.
 

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This little coil is really doing my head in. The electrical diagram doesn't always show a polarization mark; most people answering the question 'are these things polarized' say 'no' but a few say 'sometimes! Magnetic fields! CRTs!'; but the part had 3 legs; sometimes the third is connected to a circuit; sometimes it's not; the third pin isn't connected inside the component, so clearly it's just for orientation... Or stability!?

Does anyone know for sure if it matters or not? Because I have no idea which way I wound this core and I have no idea if it matters. <head explodes>
 
Well the coil was reinstalled, and capacitor C514 finally arrived and was replaced. The monitor fired back up without complaint, and everything works again. I'm very happy to have it running again!
PVM-Cap.jpg
Now to tackle this NEC PC-TV454... Slightly less help available online for this one.
 
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