My panasonic TH42PX60U won't power up. No red light flashing. Completely dead. I tried unpluging and using different power outlets. Still nothing. Any help?

Did you use a new electrical outlet? If so, have you confirmed the new outlet has power?
Did you try moving the TV back to the original outlet and confirm the TV will not power up?

Switch off the TV from remote, then switch off the on/off button on the TV, remove the plug pin from the power outlet. Cool off for 48 hours and then retry. If nothing works, better refer it to a qualified service technician.

Tries tv unplug,replug it back like about an hour later for the tv to do it resetting itself back to the factory setting,tv might work again.If not still same problems.The tv 90-95% it is the board that call the tv power supply board is having a problems.That the board where the tv power a/c cord plug into it.U have all tools and know basic electronic and also can do basic soldering works too?Yes,take the tv aparts,check the tv power supply board carefully for dying and soon to be dead capacitors components parts.These capacitors components parts are alway bulges up or puffing up onto it tops.These dying and soon to be dead capacitors components parts are bulges or puffing ups on to it tops must have to be replaced will solved ur tv power unstable and flashing red light.Or try website like Ebay.com to buy a whole new refurbish tv power supply board for the replacement.

The power supply board is dead.That the board where,the power a/c cord plug into it.Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish power supply board for the replacement.

U have sound at all?Yes,than ur LCD INVERTER backlight board it dead.If power LED light keep flashing nothing on,sound or picture.Than the power supply board is dead.Must replaced the power supply board.Tries Websites Shopjimmy.com,Ebay.com to buy these refurbish boards.

try looking at the board inside the TV for bulged capacitors see polaroid thread. this is the problem on the polaroid could be the same here. tips and tricks section

http://www.tvrepairdoctor.com

In the majority of cases when you'are unable to power up the TV, the power supply would the first place to start.
Check this site for cheaper power supply.
Good Luck.

would require some troubleshooting, common problems would be convergence amp ic and high volt transformer transistors

If you are really brave tackle this TV FAQ.
http://repairfaq.ece.drexel.edu/sam/tvfaq.htm