Samsung PS50C450 picture issues

[jczarniak]

Hi,

I'm not sue how to describe my problem.
When changing channels, picture from previous channel stays on, still slightly visible,mainly channel logo on bright background.
Menu outline still visible after leaving menu etc...
When no signal (black background) kind of dark red patches on the screen.
Which screen board (if any) should I change to fix it.

Thank you.
Regards.

[dick_barton]

Re: Samsung PS50C450 picture issues

Post pictures of your boards and screen fault if possible.

[jczarniak]

Re: Samsung PS50C450 picture issues

y-sus:
LJ41-08458A

buffer:
Lj41-08459A

It will be difficult to capture the picture fault.
Darker shapes (shadows) on the bright background or dark red patches on the black screen (when no signal)

[vinceroger69]

Re: Samsung PS50C450 picture issues

Have you tested that all the voltages match what they say on the panel sticker one maybe a little low causing this isuue and its nice to see a new member close to me not many of us on badcaps.net in warwickshire.

[dick_barton]

Re: Samsung PS50C450 picture issues

As vinceroger69 suggests, the panel should have a label which gives various voltages which you will find on the circuit boards. VS, VA, etc. Do the voltages read from the circuit boards match?

[jczarniak]

Re: Samsung PS50C450 picture issues

Wow I'm from Bedworth, a few miles to Nuneaton
I checked the Vs and Va on power supply.
I already increased the voltage by a few volts. Nothing changed.

[diif]

Re: Samsung PS50C450 picture issues

The review here mentions the TV suffers from image retention issues.
https://www.avforums.com/review/sams...-tv-review.124
Leicester here

[vinceroger69]

Re: Samsung PS50C450 picture issues

Wow I'm from Bedworth, a few miles to Nuneaton
I checked the Vs and Va on power supply.
I already increased the voltage by a few volts. Nothing changed.

i wonder if they ever did a software/firware update to help sove this issue i guess if this panel has a good few hours on it its going too be hard to get a good image etc.

[jczarniak]

Re: Samsung PS50C450 picture issues

Hello to Leicester !
So you think, that my screen is ageing and there is nothing I can do?

[jczarniak]

Re: Samsung PS50C450 picture issues

[vinceroger69]

Re: Samsung PS50C450 picture issues

maybe but wait for more experienced members to chime in they may have other thoughts, i dont often have plasmas to work on but still read all the threads for when i do image retention is something im not sure on myself but as you have already put the voltages up a little im not sure what else you can try.

[jczarniak]

Re: Samsung PS50C450 picture issues

maybe but wait for more experienced members to chime in they may have other thoughts, i dont often have plasmas to work on but still read all the threads for when i do image retention is something im not sure on myself but as you have already put the voltages up a little im not sure what else you can try.

Thank you very much.
Let's see if there are some other opinions also.

[vinceroger69]

Re: Samsung PS50C450 picture issues

in the mean time take some good clear pictures of the boards used in your set as some members if theres no pictures wont offer help which i dont blame them as we dont have the tv in front of us we rely on the pictures provided these boards may also be used in another set we reconise.

[jczarniak]

Re: Samsung PS50C450 picture issues

in the mean time take some good clear pictures of the boards used in your set as some members if theres no pictures wont offer help which i dont blame them as we dont have the tv in front of us we rely on the pictures provided these boards may also be used in another set we reconise.

Good tip.
I'll try to take some tonight.

[Andrew F. Ali]

Re: Samsung PS50C450 picture issues

Measure the Ve - Erasing Voltage generated at the X-Board and derived from the Vs voltage. Ve is 95-100Vdc. Primarily used to assist the Y-Board in erasing previously activated cells and neutralizing the erasure before the next scan.

[dick_barton]

Re: Samsung PS50C450 picture issues

The review here mentions the TV suffers from image retention issues.
https://www.avforums.com/review/sams...-tv-review.124
Leicester here

Interesing review. Would go along way to answering one of the issues.

[jczarniak]

Re: Samsung PS50C450 picture issues

Measure the Ve - Erasing Voltage generated at the X-Board and derived from the Vs voltage. Ve is 95-100Vdc. Primarily used to assist the Y-Board in erasing previously activated cells and neutralizing the erasure before the next scan.

Very interesting.
I'll measure tonight.
Thanks a lot.

[jczarniak]

Re: Samsung PS50C450 picture issues

Measure the Ve - Erasing Voltage generated at the X-Board and derived from the Vs voltage. Ve is 95-100Vdc. Primarily used to assist the Y-Board in erasing previously activated cells and neutralizing the erasure before the next scan.

Hi,
Is there test point on x-board to measure Ve voltage, please?
If not, how can I measure it.
Thank you.

[Alastair E]

Re: Samsung PS50C450 picture issues

Yes--Its marked, Ve. There's a small pot near the TP for setting.

Worth checking VSC on the Y and that the Vs is correct.

These panels at this age also show poor discharge especially when cold showing up as a grainy picture--like its projected on black sand. Nothing much you can do about that, its just age related Mal-Discharge.

The IR you're experiencing seems also related to age when all voltages are correct, Prolly one of the poorer samsung panels the worst being the E series...

Oddly, the 42" C isnt half as bad, Dunno what they did wrong on the 50"

[Andrew F. Ali]

Re: Samsung PS50C450 picture issues

Let's see...The Y- Main Board is the left board and the X-Main Board for Samsung Plasma TVs is the board on the right, if looking at the TV from the back. So there should be a Test Point labeled Ve somewhere on the X-Board. Loss of Ve will cause the symptom you are having. For a quick fix replace the X-Board.