Sony PVM 20M4E, powers has audio, no picture.

[LordBarker]

Picked up a large PVM haul today! And having issues with the 20" PVM, 20M4E. When I powered it up it displayed fine, then all of the sudden the picture went off. No sounds, no popping, just died. When fed an RGB signal with audio the audio works fine. I just wondered if there are any obvious things I should check before taking it to specialist? Cheers

[xAzurexEonx]

nice I have the 20M4U (same).

open it up and check the neck board (C board) with is the one attached to the tube. check for any signs of broken solder joints, board cracks, damaged resistors. any of these issues will not allow the guns to get powered.

if the board is cracked do not fear as its very easy to bridge the board back together (one of my own and picture is perfect).

[LordBarker]

Thanks mate, checked all that. I'm wondering if it's a good idea to cut the mastic off and reseat the neck? I've been told could be a current limiter issue.

[xAzurexEonx]

You could try, however I'm sure it won't do anything (but stranger things have happened). Unless a pin is broken or somehow corroded, it is VERY well seated. There is a brightest dial in the left corner, if set wrong will either make screen look like it is off or actually turn off and give you a warning light.

you could also see if the guns are heating up. you'll see a soft orange glow if they are getting power. then you'd know if you are dealing with a simple current issue.

[LordBarker]

Thanks man, when you say the guns are they quite hard to see and located on the tube itself?

[xAzurexEonx]

"Guns" are what is inside the glass tube that connects to the neck board "C". You should be able to see through the glass.

you can see the tiny orange speck, in person you'll see more.

https://ibb.co/gvbwia

[LordBarker]

Thanks mate, yes they are firing. I left it with a buddy earlier who used to repair these so there's hope yet!

[xAzurexEonx]

Hey bud, did you get your unit up and running?

[Elrinth]

I have this exact model and my issue is that I have no audio

image works perfect tho. I soldered the board from a different PVM as it wasn't broken in half.

Please tell us how your progress is going. It might be something stupid as previous people mentioned (corrosion on some traces or similar).
Might it also be caps?

I have this exact problem with my Bang Olufsen MX4001 where the tv works starts.. But after a short while, it just turns off. I have read on interwebs that there's big possiblity that a trace somewhere is off. Maybe you have same problem, but yours is still on, while my B&O turned off itself. Identifying these traces aren't super easy. There's overwhelming much electronics stuff in B&O, I don't remember if it was that bad in the PVM. If I remember correctly it's much easier to handle.

[xAzurexEonx]

The PVM is probably set on USER PRESET. This will not allow any audio as this setting is suppose to be tied to the optional remote. You can go into menu and change it to another preset and audio and full controls should appear (if issue).