PVM-2950Q issue

[unmaker]

I was ecstatic to find a PVM larger than 19" in my area on Craigslist. I checked it out in person and it looked great to me. The owner also threw in 2 speakers for free (which I later found out were unshielded). Got it set up at home and started gaming when I noticed that the left side of the screen was dimmer and looked washed out compared to the right side. Depending on what colors are on the screen, it varies from hardly noticeable to very noticeable. I'm worried that this is an issue that cannot be repaired and will progressively get worse over time.

This screenshot is from the intro to Demon's Crest taken with my crappy phone

http://imgur.com/a/YBTLJ

Any input on what this could be and if any possible solutions exist would be greatly appreciated.

[xga]

The Sony PVM-2950's are getting on in years now (well over 20), so depending on the life that it's had, the chassis may require a re-cap, as some of the electrolytic capacitors may have either leaked or dried up.
Unfortunately there's no way to tell the number of hours a PVM has done (unlike BVM's). I've seen some 2950's that look brand new and others that look quite poor (dim colours, excessive blooming etc).

[unmaker]

The Sony PVM-2950's are getting on in years now (well over 20), so depending on the life that it's had, the chassis may require a re-cap, as some of the electrolytic capacitors may have either leaked or dried up.
Unfortunately there's no way to tell the number of hours a PVM has done (unlike BVM's). I've seen some 2950's that look brand new and others that look quite poor (dim colours, excessive blooming etc).

Thanks for the input. Mine has a sticker over what I think is the original manufacturing date that says "July, 2000". I'm not sure if that's some kind servicing date but it's still quite old.

[xga]

The 2950 first came out in 1994 from what I understand. You might be lucky and have one of the later manufactured ones, but it still could have done a ton of hours if you don't know its history.

Another good way to tell the date of manufacturer is to have a look at the sticker on the tube or the metal shielding around the tube. A lot of them list the year and month of manufacture.

[andy251203]

I have a 2950Q so I'll chime in. The chassis is built closer to a traditional consumer TV chassis, and uses standard grade 85 degree capacitors. These caps will wear out a lot faster than a traditional PVM, so you'll probably want to replace them. Beware though, this chassis is huge and quite a pain to take apart and put back together.

I also had some issues with cold solder joints affecting the pincushion adjust PCB, so make sure to touch up those solder points if you're doing repairs.

[noonan2678]

I have one as well and have been lucky from a color, contrast and brightness perspective. The geometry is so hard to get, specifically an area in the top left of the image that is just bowed in. I've adjusted as much as I can, short of an ISF calibrator coming in. Do you guys think caps could fix that type of issue?

[unmaker]

I have a 2950Q so I'll chime in. The chassis is built closer to a traditional consumer TV chassis, and uses standard grade 85 degree capacitors. These caps will wear out a lot faster than a traditional PVM, so you'll probably want to replace them. Beware though, this chassis is huge and quite a pain to take apart and put back together.

I also had some issues with cold solder joints affecting the pincushion adjust PCB, so make sure to touch up those solder points if you're doing repairs.

Happy to hear that this can be fixed with soldering though I would probably get myself killed attempting this. I've never opened a CRT, don't know how to properly ground, and my soldering experience consists of replacing the 3.5mm jack on my headphones. Maybe in the future when I learn a lot more I can try this out.

[ryu]

You're not gonna be working on the machine while it's running. Should be fine if you let it sit for a while and even if there's a charge remaining somewhere it won't outright kill you.

My suggestion is wait a few weeks and take your time disassembling the thing, make sure to take notes so you know how to reassemble it potentially weeks to months later. Take note of the capacitors you need, get your hands on them and then do some practice on throwaways PCBs before you work on the real thing. This is by far no impossible job if you have the time and patience for it.

I have two 29" NEC multisync monitors that need to be recapped, you can't imagine what a nightmare of a repair job that is. :/

[andy251203]

There is probably 100+ capacitors on this chassis. I would strongly suggest having a good desoldering gun handy if you decide to recap this beast yourself. The Hakko 808 used to be the best budget desoldering gun, but it has since been replaced with the FR-300. I use the FR-300 myself and it works wonders.

I wouldn't worry about shocking yourself when servicing a PVM. PVMs have CRT discharging circuits built in, so you don't have to worry about manually discharging the CRT. In fact, you won't see anything written about manually discharging the CRT in the service manual!

All that being said, if you are a novice at soldering, I would suggest having someone more experienced service it for you. You wouldn't want to ruin a potentially good PVM.

[ELabit]

Just gotta ask though, have you degaussed it yet?

[unmaker]

Thank you all for your input. Would probably have to find someone else do this for me. Spending several hundred dollars on decent soldering equipment to botch my PVM would not make me very happy.

And yes I have degaussed it several times. Was the first thing I did when I noticed the issue.

[mvsfan]

Yeah, the old Pvms like your 29" have lots of boards in them and lots of caps.

the newer designs usually have 2 boards and a fraction of the caps.

Btw, large caps can still shock you good if they are charged. Im not sure if these older pvms have an automatic cap discharge built in. some of the newer ones do.