I haven't taken apart my LCD and I'm not gonna, but what makes them tick?
I can see where the LCD/plasma going bad can call the game, but isn't there other circuitry that can go bad and be replaced, or the odds against that?
Unless, of course, they are all on one big, soldered PCB which makes component level troubleshooting near impossible?
The reason I ask is that I made $$ in high school in the 60's with a small home TV repair shop and most of the fixes were bad tubes. Troubleshooting was another story but it could be done. I got out when SS came into play and modules came into play. No way a little giuy could afford to keep stock of them.
I'm not a technician but I work at one of those rare repair shops and in my experience LCD and plasma TVs have been extremely reliable. That said, we don't work on Westinghouse, Olevia, Polaroid, etc. mainly because our suppliers do not supply parts for those brands. We only sell brands that we have found to be reliable. Mitsubishi, Sharp, Panasonic, Sony, Pioneer, Pioneer Elite, Samsung (LCD panels only). Of course there are other good brands out their and we to work on all the major brands except for Phillips/Magnovox which has a very poor track record.
I can only recall two LCD sets that have come in for repair. One was a Sharp that was hit hard by a power surge, another was a Sony 46" XBR3 with a bad LCD panel. The Sharp needed a new power supply board and Sharp covered the cost even though it was out of warranty. The Sony was under warranty.
The most likely thing to go in an LCD is a power supply board, or so I hear. The same seems to be true with plasma sets.
Rear projection sets are a completely different story. The most common problem, by far, on CRT based projections sets is failure of the convergence board ICs. This typically costs $200-$400 to repair.
When it comes to microdisplays (DLP, LcOS, LCD) everything changes again. It varies greatly by brand. Samsung has been, by far, the worst when it comes to reliablity of their microdisplay sets. When we sold them there was an 80% failure rate. That is completely unacceptable and needless to say we no longer carry them. Light engine failure (color wheel, optics, or DM board) is the most common problem with Samsung microdisplays. Replacement light engines start at around $600 and go up from there.
Sony has also had light engine problems, though not to the extent that Samsung has. The green blob is widely documented in online forums and I am here to confirm that it definetely does exist. Luckily Sony is fixing them at no cost. Some Sony LCD RP sets have suffered from what I call the star field effect where the blue LCD panel fails and blue dots grace the screen.
Mitsubishi had what I would consider a lemon about two years ago. The WD-**525 series was their most troublesome line we've ever encountered. It was mostly DM boards.
TV repairs are expensive. My advice is to stick with a name brand with a good reputation. If you're really concerned I would get an extended warranty, especially if you're purchasing a microdisplay set.