pioneer pro-506 XMain issue

[freakaftr8]

Hey all.
Well I picked up this pioneer plasma the owner said the screen was black. This has standalone media receiver. So I connected it all together when I got home and long and behold sure enough black screen I can see the screen trying to light on the corners barely and I can hear that sustains working but no picture so I don't know still a little bit and checked voltages are all there. I left the TV on with a video signal being fed to it well I was on the internet searching for schematic. All the sudden I saw something on my corner of the corner of my eye the screen started to come back but it was the corners first into the centeruntil the whole screen came back after about 10 minutes later. So I'm thinking X Main. anyone seen this before on a pioneer?

http://i845.photobucket.com/albums/a...ps4e1f2fb3.jpg


http://i845.photobucket.com/albums/a...psc266948c.jpg

[tom66]

Re: pioneer pro-506 XMain issue

Yeah that's pretty much a bad x-main.

One thing to check would be the Vsus voltage as well as the Ve/Vzbias voltages (not sure what Pioneer call it.)

If it does not use series combined energy recovery there is a quick test for X-main performance, using a voltage check.

Could be bad cap for 15V or 5V on X-main.

[cadiman]

Re: pioneer pro-506 XMain issue

The media receiver is worth more than the panel.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Hmm it does have two ipm modules on each sustain board. Just have to find out which one controls energy recovery. Vsus is 221vdc. Dont know what it should be on this panel but sounds about right. No label. Vadr is 61v. That sounds right.

[tom66]

Re: pioneer pro-506 XMain issue

221V is extremely high for even a modern plasma. The highest I have seen is 217V.
You would probably not be looking at ER-IPM fault but more likely SUS-IPM.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Ok. Trird the old heat gun approach with set cold. came up quicker. Also noticed that the screen comes back faster cold then the first time I powered it up. 3 minutes compared.to the first.fire up of 15 minutes.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Thinking possibly a dry capacitor in the x main.

[tom66]

Re: pioneer pro-506 XMain issue

Yeah, check all local 15V/5V etc supplies especially the ones near the IPM.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Found it. It appears to be a small tantalum in the y sustain oddly. Im looking for a sub now.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Actually it appears now it is a 350v 3.3uf on the 15v rail on ysus

unfortunately I don't have that capacitor I do however have is 350v 10uf that's as close as I can get.

[tom66]

Re: pioneer pro-506 XMain issue

I very much doubt a 350V cap would be on the 15V rail. But it could be the Vset voltage. That could cause this issue. Vset is usually around 2xVs.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Ok after everything I went and replaced both 3.3v 350v lytics on th r ysus. That brought the screen back mostly. A little dark in the center. But I had to ramp up the vsus to 240v from 221v and screen is perfect. I know it sounds high. Does anyone have a confirmation on what vsus is supposed to be on this model plasma? Im a.little worried about vsus being so high but man does it look good

[freakaftr8]

Re: pioneer pro-506 XMain issue

there's always a possibility that it could be a tired panel

[tom66]

Re: pioneer pro-506 XMain issue

I think a 240V Vsus is insanely high and likely to lead to sudden panel cracking due to excessive heat - tread carefully.
I very much doubt the panel is tired.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Tom you're correct. The high voltage worries me too. Normally it looks like it should be set around 200-210 v. the fact that it was the 221 tells me somebody was already in here messing around with it considering that when I bought it there were no screws on the back cover it was taped on. So what I'm going to go ahead and do is recap the Y sustain since I found two caps out of spec. turn down the vs voltage back to where it should be and see if I get a better picture. I think what I'm doing is overriding the initial problem by giving the board more voltage to overcome a lazy capacitor. Does that sound about right?

[tom66]

Re: pioneer pro-506 XMain issue

Does sound like it. Can you post a pic of Y-sus; maybe it's possible to locate the Vset voltage?

[freakaftr8]

Re: pioneer pro-506 XMain issue

Im at work away from the tv. Here it is thou.


http://cdn2.bigcommerce.com/server59....1280.1280.jpg

[freakaftr8]

Re: pioneer pro-506 XMain issue

Btw those two potentiometers had no affect.

[freakaftr8]

Re: pioneer pro-506 XMain issue

Well believe it or not. I have probably repaired at least 100.plasma tvs thus far and never seen anything like this. Panel has 67,000 hours on it. Had another pioneer here so played the swap the boards game. Its the panel .238v brings it back to life.

On a good note it doesn't get much hotter than a 64" samsung 3d plasma I have here after 6 hours of operation. Tested with a laser thermometer. 117 to 120 deg f.

[mmartell]

Re: pioneer pro-506 XMain issue

Excuse my thick skull but what does the .238v refer to or rather how was it injected to fix the panel ?