I have been repairing plasmas for the past year and very familiar with the core plasma components of this tv. Here are some troubleshooting tips that i have gathered after fixing about 15 purchased broken off ebay or craigslist
-No power light, no click, no response to plugging it in, then fuse or dead powers supply
-Turns off randomly or during bright scenes - power supply dying
- ticking or buzzing that gets faster when brigght scenes, listen for sound, most likely power supply
-turns on normally but picture dim, grainy, or slow refresh - listen for ticking noise coming from xsus board- replace xsus board
- turns on normally but no picture , perhaps a small amount of very dim speckle once on - replace ysus - its possible the ysus can also tick, ticking always comes from part under the heatsinks
-turns on normally but piicture is distorted wherever picture is on screen - y buffer boards need replacing upper and lower - kind of looks like when a nintendo game messed up and froze, it would have all these wierd distortions then you would have to remove and blow into it.. kinda like that..
- if there are verticle black or clored bands or half the picture missing, its the x buffers on the bottom or the Plasma control board - located under the video input board
- if picture is flickering and colors are way off - could be ysus or plasma control board
- if there are blue or red specles in black areas, ysus voltage adjustment is needed or the plasma panel is going bad, voltage adjustment is temporary fix
-if there is trailing blue or black speckles like a delayed shadown, its prob the plasma panel and voltage issues
Many times strange sound can point you in the right direction. also get a fuse tester as sometimes a board will go out and its just the fuse, there is one fuse on the power board and 2 on the ysus, one is for the ysus and the other is for the xsus.
Another tip, i have purchased many different brands with the same lg plasma panels. vizio, toshiba, akai etc have used these same model plasmas for years and can be found in many different models.. and sometimes you can get another broken tv for cheaper than just buying the part, just make sure its local and you can pick it up.
good luck to all of you, right now i have a vizio p50hdm and a toshiba 50hp66 that have the same exact internals and i brought back to life after having that same pop of death.