Does anyone know where I can find the service manual (if it exists) for the Sharp LC-15SH7U?
When you hit power, the red light comes on for a few seconds and the unit shuts off. I probed a few labeled power supplies, and it appears they come on when the button is pressed but are low. The unit failed during a power outage. The replacement main board is about 200 bucks, which isn't worth it for a tv like this.
I don't mind paying for the manual, I just can't find it.
Thanks, Steve
LCD TV psu's are covered in protection circuits. They will shut down if you as much as look at them wrong. The first move with one that shuts down after a few seconds, is to unplug the backlight inverter from the 24v output, as it is common for these inverters to fail and load up the supply. If it then stays on, you have a backlight problem. Another favourite is the audio output IC, usually also hanging on the 24v rail. Also, look very carefully at all of the electrolytics on the board, particularly any that are close to any heatsink, or other hot-running components. Checking them with an ESR meter is the way to go, but you will often find that the tops of any bad ones, have started to 'dome'.
Beyond this, it tends to get complicated, and if the problem really is on the supply itself, a schematic, and a lot of experience with LCD power supplies, is pretty much essential to standing any chance of getting a fix. Good luck with it.
Arfa
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