I got a free broken 32″ LCD TV from my friend. It’s a measly 720p @ 60Hz, but I’m not complaining because it was free! Anyway, it’s about 2 years “old” and has had problems before. The last time I saw it working, he had a steak knife wedged in the tiny gap next to the power button to keep it turned on (I know right?!)
I pretty much scoured google for answers and I couldn’t find a service manual that was free. I did however find out that these TVs have a series of self checks, pretty much like computers and their POST function. POST stands for Power On Self Test. The TV checks all systems and if anything is wrong with any of the internal components, it’ll shut itself off to prevent any further damage.
The TV in question is exhibiiting similar problems. When I hit the power button, the unit turns on and the power LED turns from red to green. For about 10 seconds you can hear audio from the speakers, but the display remains black and the unit shuts itself off.
I’m pretty much assuming that the problem relies somewhere on the video board or on the secondary power supply. What I think is happening is that the when TV turns on and sound comes through only because the speakers don’t draw a lot of power. Try it on your on TV, for the most part, the sound should come through before the picture is displayed. Since it takes a lot of juice to show images on the screen (either juice from the backlight or juice to power the display) there must be something wrong with those two components. Most TV’s run two or three power supplies, depending on the size of the unit.
One supply controls the inverters (which in turn powers the picture), one for the backlight, and one for the sound. Actually, I don’t know what the heck I’m talking about so I’ll just leave it up to the professional repair people. Usually I’m a DIY kinda guy, but while I was checking out YouTube, there was a video titled, TV Repair Man Gets Shocked and although it wasn’t that big of a shock, I’m reluctant to try since I might break it even more. I know about the risks of working on a CRT monitor or TVs (stupid capacitors), but I wasn’t too sure about newer sets.
I submitted the symptoms to two different local repair shop’s around San Francisco and the Bay Area. Whoever gets back to me first will have my business. I’ll post my findings!