No picture sound only
Very likely that one or more of the 3300μF (10v) capacitors in your power supply have failed and require replacement. If you're proficient with a soldering iron and other tools, it should be an easy fix -- less then $10.
I had this exact same problem recently (no video, only sound), and when it was happening, initially turning the unit off and back on resolved it. This subsequently (within a few days) developed into a problem where the TV wouldn't turn on at all (try to turn on and LED would turn green and relay would click, but a second later the LED would turn back red and another click would be heard). It would require 50-75 "power-on" attempts before the TV would stay on, and even if it did, sometimes there was no video. Finally (a few days after that), my wife heard a "pop" (she called it a mini-explosion) while the TV was on, and then she lost video/audio altogether. The TV wouldn't power on at all anymore -- it became stuck in a cycle where the relay would just click on and off until unplugged.
All of these could be traced back to some blown capacitors in the power supply module. On my 50PC5D, there were 6 caps, all 3300μF, 10V, 105°C. Five were clustered together, and one was on its own, but all 6 had split open at the top and leaked out electrolytic solution (fortunately due to location/orientation, no damage resulted within surrounding components). I replaced all 6, and now the TV is working like new again.
New capacitors at a local electronics supplier were about $1 apiece, so it was slightly more than $6 to replace them all. I would definitely recommend inspecting all caps in the power supply (there aren't that many... maybe a dozen or so)... if they're bulging even slightly, just replace them while everything is opened up.
I don't recommend buying a "repair kit" from eBay or the likes, since many of these contain insufficient parts and tend to be over-priced (e.g. I ordered a "kit" for my specific board for $25+S/H that included 4 caps, 2 FETs, and a fuse, but it would not have been sufficient by itself (needed 6 caps), plus the FETs and fuse were fine; in my case the TV died completely before the kit arrived in the mail, so I went about sourcing the parts locally). I thought I was taking the easy way by pre-ordering parts while the TV was still semi-working, since the TV was wall-mounted and I didn't want to take it down; however, I wish I had just pulled it and identified the parts needing replacement.
Jun 30, 2011 |
LG 50PX5D 50 in. Plasma HDTV