Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

[kburks1230]

I just put a ysus and y buffer in this 2009 Pn50b550t2f. Got the parts off eBay. It was doing the typical sound but no video before. Now I have video but it's looking like the attached image. What now should I do? Any ideas?

[tom66]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Try the test pattern generator on logic board
https://www.badcaps.net/forum/showpo...61&postcount=2

I fear the panel may be toast. At any point, did you reconnect the small connectors coming off the Y-main or X-main going to the bottom of the panel without discharging the Va below 10V? Especially damaging if Va was fully active at the time.

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

I didn't Tom. The test patterns have the same distortion on the left side of the screen.
I did forget to plug in the power from the ysus to the bottom horizontal boards at first. I powered down though and plugged that in. Which is where I have this problem.
Definitely a bad panel?

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

The heat sinks on the x and y suspend boards are getting very hot...

[tom66]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

The X- and Y-boards cannot cause this. You can try a control board replacement but I think the actual plasma panel is shot due to Va transient.

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Is there any way to know except throwing a control board in? Can a bad panel fry a Y-board? What would you do Tom?

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

I found a control board for $10 on ebay. If this doesn't work I'll pull the boards for future repairs and ebay.

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

TV is working with the new main board.

[tom66]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

I'm quite surprised! Great to hear.

[freakaftr8]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

You mean you replaced the main board or the t-con board?

[tom66]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Given the fault appeared on the control board (=t-con) test patterns too (independent of main board) I guess OP means control board.

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Sorry yes the tcon board

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Is there a procedure to adjust the three pots on the y-board without an oscilloscope?

[tom66]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Yes, do you have mal-discharge? It is usually done by eye.

For positive mal-discharge - pixels lighting when they should not - adjust Vs and Yfr, in that order.

For negative mal-discharge - pixels failing to light - adjust Vs, -Vsc, Yrr and Yfr, in that order.

The Vs and -Vsc should be adjusted according to the panel label. The other controls should be adjusted by looking at the screen. If the adjustment makes the picture better, but not as good as it can be, then try the other adjustment.

[kburks1230]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Thanks Tom, I can also see a home shopping channel burn in at the bottom of the screen. Jeez this tv has been through it all!

[tom66]

Re: Samsung Plasma Vert Half Screen Issue - Pn50b550t2f

Nothing you can do about that...if it is image retention it will go away but if it is burn in it is there for good.