When I tell my story you will either think I'm crazy or really persistent. I picked up 3 plasma's for $100.00 and fixed and sold 2 and the only one remaining was the 50pc5d which had no power. Simple diagnosis was power supply had no output. I picked up a power supply on ebay and now I had all my voltages and relay would click and fan would run, but no display. I figured the y sustain ipm's were bad so I ordered them thru a china distributor that I had used before. I have been pretty successful replacing ipm's using a heat gun to preheat and a desolder gun to clear the solder and they pull off pretty easy. Have done about 10. I also bought new? buffer boards because I didn't like the reading I got off the old ones. Used the Coppell tv test. Got every thing done and got a picture. Pulled up the menu and after about 5 minutes the screen started flashing and then it went pink/purple but I could still see an image of the menu. I removed the bottom buffer and the top half was still good. I checked the lower buffer and two fet's were bad. I replaced the fet's and reinstalled the board and normal picture again for about 5 minutes. Then the same thing happened but this time it flashed on and off repeatedly. I removed the lower bufffer and now the top half still flashes pink/purple display and you can still make out the menu. So now both buffer read bad fet's. I checked Vy and Vscn and the voltage was steady and about 1 volt off the panel label. I hate to get two new buffers only to get them wiped out. Almost think its a bad ipm but thought I could use some advice on what to check next. I did check the ribbon cables and all connections. So am I crazy and should I just scrap this or?? I feel now like its a quest to go ahead and keep going. Thanks
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Last edited by gdawg; 07-29-2014, 10:21 AM. -
Re: 50pc5d LG Plasma
Didn't hear back from anybody and I believe I fixed it through persistents. I was replacing the ER IPM on the y sustain and was checking my solder work for bridging. I was looking thru a magnifying glass and just happened to see a cold solder joint on the ER caps-the orange ones. I could move the lead with my finger nail. I guess I over looked the obvious. Thought I 'd post my results for anybody with the same problem. You could not see it with the naked eye. I also guess thats what was blowing the fet's on the buffer boards. Thanks -
Re: 50pc5d LG Plasma
Wow gdawg,
you are persistent. I have a no power on same model. Free tv. Will inspect the insides and check back with you. May be you can assist in the testing-diagnosing steps.
thanks for ur postingComment
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Re: 50pc5d LG Plasma
gdawg. Hello. My name is Gregg and I'm over here in Gilbert AZ. I have a Panasonic TC-P58S2 then recently went out. I found some "Blink Code" info on line (7 blinks) and was searching for more information on line when I stumbled onto the site. I then noticed you'd had the same issue with the same model and was wondering if you'd actually fixed your issue. If so I was wondering if you'd be kind enough to tell me what board you'd replaced (or fix) so I could buy one and fix my TV. Any help would be greatly appreciated. Also you may call me on my call phone at 602-614-6294 if you'd like. Thank you in advance.Comment
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Hi all,
I'm interested in understanding how a buffer board chip is working. I know there's about 90 outputs per chip to the plasma panel, but I'm more interested to know about the input pins. I guess that some of them are address pins, but I want to know more.
So far I've found nothing at all. I haven't found any datasheet about the various buffer chips, and I haven't found any schematic for the buffer board using them (Y Buffer Board in Samsung's terminology).
Any information will make me happy. It can be from any buffer chip or plasma TV manufacturer.... -
All left and right refers to looking from rear of TV (or looking from front with TV upside down)- TV came with vertical bars and no image. Found faulty TVS on left buffer board. Also replaced T-Con (may have damaged the original while hot air removing components, board has slight warp) and have full image but few horizontal lines on the screen. Some of the lines appears to be 2 pixel tall while others are 1 pixel tall.
- Disconnecting left and right buffer board potentially reveals problems on both sides with different signals (unless this T-Con require jumper like Samsung FB_TRDY1&3) Fault
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Problem
This is an LG edge LED lit LCD Display. The LEDs are on the bottom edge of the display. There are 2 bars (left and right) Each bar has many LEDs and a 6 pin connector. Each pin drive several LEDs thus is the highest current flow / heat junction. The weak lead free solder gradually fails with thermal expansion/contraction cycling and increases resistance. PSU will compensate up to a point, then when the current is too high, PSU just shut down the backlight causing a dark display. I have even seen one which the connector just fell off as solder points became completely detached.... -
Background:
I have a LG 50PA550 Plasma TV which stopped displaying a picture. The sound works just fine. The outputs of the power supply board were within 2% of the expected values. After removing the Y top buffer the bottom half of the TV started working.
Question:
Do I have to order both a Y-Buffer and Y-Sustain board to fix this?
Could I somehow check the Y-Sustain board to see if there was any damage done to it? -
Picked up a bahemoth plasma TV not too long ago and just now getting around to looking at it.
No picture but you hear the TV static (white noise) playing loud and clear.
The back was already taken off (and no screws were provided) as the previous owner had already taken a look.
But it seems they didn't get too far and just left it.
When I first took a look I was amazed at how pristine the inside looked.
Its as if the TV had been in a time capsule.
Caps looked like they were just pulled off the self.
Copper coils had no sign of corrosion on...
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