Samsung PN58A55081F sparkling pixels

[rodzghost]

Hello,

I inherited a Samsung PN58A55081 Plasma TV, and it has colored pixels sparkling all over the screen. I did a little research and think it may due to bad caps on the power supply.

Here are some pics:

EDIT: Sorry, I posted the wrong links for the pics. Here the correct links:

[IMG][/IMG]



I've never done any sort of TV repair, but I have worked on computers and other types of electronics. I do have a few questions before attempting to fix this.

First, I read that a 10 W wire-wound resistor is sufficient for discharging the power supply caps. Would I just plug the pins of the resistor into the connector for the board? And does polarity matter, as in can it be plugged in either way?

Also, does anyone know which capacitors this particular power supply uses?

[braz508]

Re: Samsung PN58A55081F sparkling pixels

pictures are not loading for me.

[Alastair E]

Re: Samsung PN58A55081F sparkling pixels

Unlikely caps on the PSU will cause Mal-Discharge, --which is what you're describing, if all the output Voltages are correct.--Have you checked Vs and Va...??

Probably the panel itself has aged, How many hours on it? Worth checking all the supply and Y-SUS voltages, such as VSC, -Vy Vs and Va etc.

Maybe a very careful adjustment of Yfr and Yrr will help, or a slight reduction in Vs voltage...

[rodzghost]

Re: Samsung PN58A55081F sparkling pixels

Unlikely caps on the PSU will cause Mal-Discharge, --which is what you're describing, if all the output Voltages are correct.--Have you checked Vs and Va...??

Probably the panel itself has aged, How many hours on it? Worth checking all the supply and Y-SUS voltages, such as VSC, -Vy Vs and Va etc.

Maybe a very careful adjustment of Yfr and Yrr will help, or a slight reduction in Vs voltage...

Are the voltages all marked on the PCB's? I haven't cracked open the TV yet. I can check them with my meter once I take it down.

The TV is from 2008 and has a lot of hours on it.

How would I go about adjusting Yfr, Yrr,Vs?

[Alastair E]

Re: Samsung PN58A55081F sparkling pixels

All voltages marked on Panel Label.

7-8 year old panel will prolly be very worn, which is what I suspect by looking at the pictures, those almost stripes of M.D. down the screen, caused by manufacturing tolerances of the glass and the cells....
Patches of M.D on Old Samsung panels seems to be fairly common in sets made later than the xxQ96/7HD series, which is odd as Ive not seen any defective panels in this older (Q96) series....