Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting TVs and Video Sources
Register FAQ Calendar Search Today's Posts Mark Forums Read

Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 05-18-2018, 11:50 AM   #1
New Member
Join Date: May 2018
City & State: Troyes
My Country: France
I'm a: Knowledge Seeker
Posts: 19
Question Short circuit on Y Buffer board, or bad panel ?


Someone gave me a plasma TV Samsung PS50C530, which didn't turn on. It's the first plasma TV that I open and try to repair. I have repaired some LED TV but it was mostly simple things like replacing backlight or capacitors.

I found shorted components, and an exploded disk capacitor, on the Y Main board, so I bought an Y Main board on ebay, but when I installed it in the TV and tried to turn it on, it blew up instantly. All I saw was a few random white pixels on the display, then I heard "pak" from an unknown place (can't see any damaged component on any board) and now the "new" Y Main board shows the same problem as the old one, with shorts on multiple components. I also checked Va and Vs (with Y Main board disconnected so the SMPS could start) and those two voltages are good. I know the TV sound is working because I connected a HDMI cable, turned the TV on (still without Y Main) and could blindly select the HDMI input withthe remote, and heard the sound from it. Also the LED on the Logic Board flash at 1Hz.

So I think the problem might be, either a bad panel, or a bad Y Buffer board. I did the Y buffer test as shown in youtube videos:

But couldn't find any shorts (I tried with all other pins on the white connectors too).

However I think I've found that all "big" diodes and resistors are shorted:

My multimeter beep when I touch the two side of diodes like the one in this picture. This is bad and shouldn't happen, right !?? I tried to remove the diodes but the shorts are still here after removal. When I measure resistance across these resistors I always get around 2 ohms. As you may see I've removed the hot glue from a chip but not sure what to test here because I don't find the datasheet for that chip (Panasonic AN16489A).

Do you think that this Y Buffer board is bad and caused both Y Main boards failures ? And may it have originated from a bad panel ? I don't see any damage on the panel itself, however the TV bezel is damaged like if it felt on concrete or gravel:

I'm wondering about buying a new Y Buffer, and again a new Y Main (and also X Main maybe, however I can't find any shorts on that board, but does that mean that it's good?). But before I do so, is there anyway to check if the panel itself is good and won't blow up the new components instantly?

Here is a picture of the whole Y buffer board:

What do you think about it? Thanks!
Attached Images
File Type: jpg 1.jpg (665.0 KB, 104 views)
File Type: jpg 2.jpg (684.5 KB, 104 views)
File Type: jpg 3.jpg (133.1 KB, 106 views)
File Type: jpg 4.jpg (474.3 KB, 104 views)
guix is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump Technical Forums 2003 - 2022
Powered by vBulletin ®
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 03:26 AM.
Did you find this forum helpful?