PN51E550 dark cloud, poor image and flickering brightness (with videos)

[TechNinja]

Hey everyone, really glad i stumbled on this website. Been reading a lot through the forums and this place seems to be promissing on figuring out what i need to do with my plasma TV.

I bought a PN51E550 early January 2013 only to have a volunteer fire fighter burn down the building (arson). Our apartment was the most affected and my new TV was most likely dunked underneath lots of water, if not, then sprinkled with water for 4 hrs. Once i was able to retrieve my plasma i flipped it on and it SEEMED to be working just fine but after about 15 mins i started to get a dark cloud across 90% of the screen, what looks like dead or missing pixels and the screen keeps flickering brightness. Whenever the screen gets bright the picture is clear. I have aired this out for about a month or more and moved it around to be sure there wasnt any water inside. Havent opened it up yet because i havent seen this kindve issue before (im a communication technician with a bit of background in electronics) and its hard to describe. I made 2 videos in hopes that i can get some clarification on the problem im having so i can get pointed in the right direction. Thanks everyone

https://www.youtube.com/watch?v=ptET...e_gdata_player

https://www.youtube.com/watch?v=VBYY...e_gdata_player

In one of the videos i wanted to clear something up and say thank you for tom66 and his detailed post about repairing plasma TV's and whats inside making them tick

[TechNinja]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

I have a volt ohm meter and was wondering if there was a way to test and see if all voltage and current has discharged so i dont get zapped?

[capkid]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

What were you planning on doing after discharging voltages? The power supply, Y-main, and X-main are the boards that house the most dangerous voltages. You can check voltages at the connectors with your meter. The high voltage capacitors are the components that need to be discharged. You can do that using a high wattage resistor (5 to 10 ohms), a screwdriver across the caps' neg and pos leads (my least favorite method), or using a 100-watt light bulb in a socket that has neg and positive leads. If you are unsure after discharging caps, use your meter to verify they've been discharged.

Edit: If your plan is to do some testing, and you're not intending to remove any boards for now, you don't need to discharge any voltages. Just avoid touching the high voltage caps with any part of your body.

[tom66]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

I would check, in order: Vs, Va, Ve and -Vsc voltages while set is running.
And then I would try activating the test pattern modes.
https://www.badcaps.net/forum/showpo...61&postcount=2

This is a very new 2012 TV.

[Caleb]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

Smoke=Carbon which is a very good conductor, add in water and all that gunk makes its way into all the nooks and crannies in the circuit boards. I have fixed 2 lcds that went through a house fire and while unaffected by the flames there was a lot of stuff that needed cleaned off the boards. Open it up and make sure its clean before you run it for too long, if you have residue it may cause it to short out and create bigger problems. Solvent and a toothbrush work well.

[capkid]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

Yeah, smoke residue is a pain in the ass. I totally gutted one plasma that had a heavy cig odor, and I cleaned the boards in the sink with a small brush and a little dish detergent. I let everything dry for about 3 or 4 days. The smell was lessened, but it wasn't totally gone.

In this case, it sounds like the TV's components weren't allowed to thoroughly dry before it was put back into use. 99% alcohol or acetone can be used to clean the boards. Hopefully, there's isn't any lasting damage.

[TechNinja]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

Thanks for all the suggestions

I dont know where to test the Volts at. I dont see on the board test spots. Tried doing a google search but nothing is standing out.

I popped the back off and everything 'look' solid. No smoke res, no blown caps, board looks 90% clean.

video of the whole tv: https://www.youtube.com/watch?v=IttF...e_gdata_player

pics of the power board

[capkid]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

VS and VA test points are labeled on the power supply as "VS-TP" and "VA-TP" - see the right-hand side of your second pic. VSC (VSCAN) and VE are highlighted in the attached pic. To test VE, place the negative probe on one lead of the capacitor and the positive probe on the other capacitor lead.

[TechNinja]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

It was the power supply. I didnt get a chance to test those spots but since it was a suggested supsect i ordered a new one on ebay. Was an easy installation, couple of screws and 2 ribbon cords.

I was able to find a way to duplicate my problem on the old power supply. Anytime i cranked the screens "cell brightness" it would have a burn in(ghosting)/dark spots/pixel loss. If the brightness was down to 0 (out of 10) the burn in(ghosting) would be gone but to a trained eye could tell there was still some messed up pixels.

Changed out the power supply and everything is working fine - Thank you everyone for pointing me in that direction!

For anyone new or wondering if its worth the venture to fix yourself; I was quoted it would cost me a 40 deposit + parts (quoted 75 for power supply) and w/e labor. I spent 40 on ebay and swapped it out in less than 30 mins.

[freakaftr8]

Re: PN51E550 dark cloud, poor image and flickering brightness (with videos)

I would say that a transformer for the vs circuit never got a chance to cure after water damage causing the vs to dropout around half voltage. Seen this before . affects vs on the zsus.