Originally Posted by luckydriver
so why did holding the power button in fry the tv...
If you held the power button in for a while and then released it, and then plugged the TV in, then it was a fluke. Holding the power button in for a while is standard procedure. It discharges all the internal capacitors, ensuring that the TV completely shuts down and then cold-boots upon restart, as well as somehow assisting in powering back on when the TV is starting to have Y-Sustain board issues (fr at least some people, including me).
If you were holding it in when you plugged it in, you may have damaged something in the power supply board.
When you plug the TV in, it actually powers up, in standby mode. Discharged capacitors charge up quickly, the processors boots up and starts running, the remote control circuit "listens" for the On command from the remote, etc. Then when you push the On button on the remote, the firmware brings a bunch of other stuff to life.
If the button was held in while plugging in the TV, both of these stages may have started at the same time and pulled more current than the supply was designed for.
It seems like it should just be a blown fuse, since that is what the fuse is for: to blow when too much current is pulled. However, the UPS popping would suggest otherwise, as though something is shorted out now.
The last I looked, power supply board were available and not too expensive on places like eBay and online TV parts shops. You may be able to get it running again.