potentiometer to replace broke focus pot on PVM neckboard

[deezdrama]

Just recapped a pvm-1341 and set geometry/convergence, but couldnt get focus set due to a broken pot on the neckboard. Luckily I had spare parts and used a spare neckboard but would like to replace this pot eventually to have a working spare neckboard.
In the service manual the potentiometer is part number 1-230-641-21/resistor/adjustable/metal glaze/ 2.2M
Has 3 pins on bottom.... Any clue to what modern pot could be used?

[buttersoft]

Not going to be easy to locate one, for sure, unless you can cannibalise another, non-working PVM. I'm not sure how it's rigged up, but you might try the voltages on the fully operational neckboard with the pot turned to each end, and then find a pot with the required voltage tolerance. You might have to figure out some way to mount it, of course, but that shouldn't be impossible.

Just be $%^ing careful when working with the neckboard. Focus voltage is often like 8kV, and while i'm not sure all of that is going to be across that crowded spot, you may want to look at or trace out the schematics first, and, if you're still unsure, use a high voltage probe and not a regular multimeter.

[deezdrama]

Not going to be easy to locate one, for sure, unless you can cannibalise another, non-working PVM. I'm not sure how it's rigged up, but you might try the voltages on the fully operational neckboard with the pot turned to each end, and then find a pot with the required voltage tolerance. You might have to figure out some way to mount it, of course, but that shouldn't be impossible.

Just be $%^ing careful when working with the neckboard. Focus voltage is often like 8kV, and while i'm not sure all of that is going to be across that crowded spot, you may want to look at or trace out the schematics first, and, if you're still unsure, use a high voltage probe and not a regular multimeter.

I wonder if this would work...

https://www.mouser.com/ProductDetail/Am ... UnlKfv39un

Looks like it takes an allen or hex bit to adjust. I could probably 3d print little knob inserts and glue them in

[buttersoft]

Well, sure, the resistance is right, but it's only rated for 200V and 150mW. Looking at the service manual, page 40 on this link https://archive.org/details/SonyPVM1341 ... viceManual shows that the "Forcus" line is running at 900V. I would find a pot rated to at least 1.5kV if i were you. Admittedly the power rating could still be quite low.