Blue DC Power LED comes on but screen does not turn on and the power button will not turn it back off. I have to unplug it to get it to turn off. I checked the input and output of the DC power supply and I'm getting 16vdc out of the correct pins but there are no schematics in the manual and the troubleshooting section is useless
Televison & Video - Westinghouse - LTV20V2 20 in. EDTV-Ready LCD Television
Answers & Comments
OK, so you do have 16 vdc feeding he inverter board, at this point I would replace the inverter board (since the board uses surface mounted parts, it will not be easy to do compnent level repair). Hopefully you do nothave bad lamp assemblies. Also loof for component lebeled with Fxx closed to the white terminal, that is the fuse, see if it is OK on the inverter board.
Try looking here for inverter baord also:
http://www.lcdparts.net
It looks like pin 1 and 2 are for 12vdc input, there should be two pins are used for ground. One should be control ON/OFF for the inverter to light up the lamps. Do you see the sceen even flashes on at all? if it does then the ON/OFF control pin is working, then you may have lamps problem. The inverter will sense if the all the lamps conduct after the firing voltage is applied to the lamps, if on fails to conduct then it will go into shut down.
At this point, it points to the main logic board problem, the schematic will be needed at this point. I did not any free one on the web.