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 Post subject: PVM-1953MD potentially needing recap,
PostPosted: Tue Jan 16, 2018 7:23 am 



Joined: 16 Jan 2018
Posts: 1
Hello everyone,

This is my first post so I am not sure this is the right forum for it but I know a lot of what I have learned about retro-gaming has come from here.

Some background info, I am an IT geek by profession and am not afraid of simple/basic soldering (repaired many motherboards with bad caps and fixed a few LCD and plasma TVs/monitors at work). I also don't mind delving into the unknown to try stuff and teach myself new things (basically my job description) but I've never really worked on a CRT and only recently gotten more into reading basic wiring diagrams and taught myself more than soldering wires together or replacing bulging/leaking capacitors. Probably the most complex thing I've done is the NESRGB install on my frontloader.

I recently purchased a pair of pvm-1953MD from the local surplus. i was quite excited to get it home and see the improved image quality! After fiddling with them for awhile I figured out that, while they both initially appeared to be dead with only the power light turning on, they actually worked....kinda. The first one will turn on the tube if I leave it on for 5-10 minutes and looks great. The second one will come on after being turned on for a couple hours (or at least it did once). If I turn them off for an hour or less, then they will come back on immediately. If I leave them off for an extended amount of time on the other hand, such as when going to bed, I find that they need to sit "on" for the 5-10 minutes again like before. I think they are both suffering from the same issue but one is obviously significantly worse.

From what I can tell I think it could be either a bad capacitor somewhere (none that I could see appeared to be be bulgy or leaky) or, and I could be way off base with this, could it be an IC chip (specifically the IC507 the Deflection chip)? The only reason I was thinking maybe this IC chip is because when using a multimeter to follow the flow of electricity per the service manuals recommended voltage check points, it is not pumping out as much power as I think it probably should be. I am not great at reading schematics so I'm not entirely sure tho.

Only think I am fairly certain of is that the issue is not with the power board as I swapped the powerboards to see if the issue followed the board or stayed with the main unit and since it had no effect I left the boards swapped.

I currently am using and loving the one that is in better condition and have no real complaints about it aside from being bored during the 5-10 minute window between turning it on and waiting for it to effectively "warm up" enough to work, however I would like to figure out how to fix it and possibly the other one so that the problem doesn't become worse over time.

Worst part of this story is that I tried calling a handful of TV repair places to see if any work on CRTs still and I couldn't find any still in business nearby so I'm almost to the point of seeing if the local "big cities" (Seattle or Tacoma) has anyone that can/would work on them for a reasonable price.


TL;DR

I have basic skills but I got a PVM-1953MD recently and it has some kind of powering on issue....i'd guess dying capacitors but no idea, any suggestions to help troubleshoot??


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