I have a 50P8342 with simular problem

Sounds like a pressure switch or simular sensing device that is not proving positive, thus a possible vent blockage or defective sensing device.

Had simular problem with wife 2000 Jeep Cherookee.
My signal light were not working at all.Check flasher relay under steering colum

There are two main areas to look into:
A) Ignition switch
b) Netural safety switch

I had a simular problem with my car nto starting, but the alarm didn't have issues just the headlights and the radio not turning off. I replaced the ignition switch and the problem was fixed for a while until the ignition switch malfunctioned again. The ignition switch is a cheap plastic part that connects the key to the engine, and has a tendency to break. Maybe this will help. Btw, I have a 1998 and mine is not starting well, do you know anything about #3 relays? I think I may need to replace it, so that my car will start and not putter to a stop randomly while driving. The problem only arises when the car is not yet warm. Amy ideas?

Sounds like you are tripping your crowbar circuit. This is most commonly caused by one of the Red Green or Blue brightness adjustments, adjusted too high. The crowbar circuit protects your high voltage guns from getting damaged. I know this because I just did this myself. My adjustments were behind the lower rear panel in a small box screwed to the chassis. There are 6 tuning pots on mine. 3 for focus of the RGB and 3 for brightness of the RGB. The focus ones didn't seem to have any effect on the crowbar circuit. However, by turning the brightness down on each of the RGB pots I could get the T.V. to stay on indefinately.

check your alarm system and check your key

power board shot. remove power board and purchase the exact board with the numerical stamp on the board usually 12-16 characters. make sure it matches, replace board and reasemble tv and enjoy.

I have tv proyection philips model 50p8342, it is blinking red color on the power switch botton four times and then pause then another four time continuosly.

sounds like the PTV Small Signal Board.

Hi
I had simular prob,,
ended up it was my batt
got new 1 on e-bay camera fine now