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Equipment Repairs => PLASMA TV forum => Topic started by: lalunatech on March 04, 2011,00:42:40

Title: Samsung Plasma PS50Q79HD keeps blowing Y scan buffer (ydrive) boards
Post by: lalunatech on March 04, 2011,00:42:40
I have a Samsung PS50Q97HD plasma TV that keeps blowing new boards and I don't know why. It came to me with a faulty YSUS that had damaged the VS supply section in the PSU board. I fixed the PSU and fuse and have good VS voltage now. I replaced the YSUS main. I powerd the TV and the upper YDRIVE (Yscan buffer) board chips went pop. I put this down to it getting damaged unseen when the YSUS went faulty. I replaced the YDRIVE upper with new and then the lower board went faulty too (holes blew in the tops of the scan buffer chips). I replaced the lower board, now getting worried about how much this was costing me (260 pounds sterling so far!!). Powered the TV and the new upper board went pop again! I'm at a loss. Should I have adjusted the potentiometers on the new YSUS. Can a faulty ZSUS blow the YDRIVE boards? Can the panel be faulty with an internal short and blow YDRIVE boards? Any help would be very much appreciated.
Title: Re: Samsung Plasma PS50Q79HD keeps blowing Y scan buffer (ydrive) boards
Post by: watteau on March 04, 2011,06:23:09
Hello,

We had a PS50C96H  recently showing the same problem. We replaced the POWER-SUPPLY,  Y-SUS, Y-SUS Buffers, Control Panel, and the X-SUS.
The Y-SUS lower buffer blew this time. We  put the failure down to the PLASMA display.

Since then we have had at least two where we have changed the Y-SUS, and UPPER Y-SUS buffer, this solved the fault, but again the display proved faulty, as there was mal-discharge effect on the screen (all voltages etc. were set correctly).

Regards,
John
Title: Re: Samsung Plasma PS50Q79HD keeps blowing Y scan buffer (ydrive) boards
Post by: davenjax on March 04, 2011,11:29:06
hi had the same issue with a 50"philips plasma customer shelled out 260.00 quid for new upper and lower ybuffer new ysus new xsus powered up tv and practicaly anihalated the lower y buffer seems like an expensive mistake to make .dave