Hi my name is Eric, I hope I can help you with your issue , Philips makes both LCD and Plasma, on both the power supplies do go bad. One obvious way to check the power supply is by looking at it, another other is voltage tests. Because your TV turns on then off you may have a bad connection (can be checked by gently tapping the suspected area ). It could be just a few bad capacitors on the power supply, if you want to do a visual of the power board bad capacitors may appear swollen on top. On the Plasma Model the ones you are looking for are located almost center bottom of the power board,Usually I can see them clearly with the back on simply shining a light into the back through the holes. look at the photo I am uploading to see what a bulging cap looks like.
On a Philips LCD the power supply board may be mounted inside a metal shield. You will have to take it apart to look at it. Your description of whats happening does not tell me if the picture actually comes on before the TV goes off. Also what do the power lights do ? Blink on and off? turn red , green , steady light?Hope this helps, if it has solved your issue please click accept and close out the request But if you have more questions please respond and I will reply asap Thanks Eric
4 Blinks 90% sure you have a swollen capacitor issue. Can't hurt to try and save a few bucks and do it yourself.
These set have alot of screws on the back, not regular screws torx 10 mostly.
Also the Tv is heavy and you can crack the screen so lay it down on a soft quilt before starting, remove the stand and then the middle back section.
Open the back and check the capacitors on the power supply, if you want to attempt the repair yourself you can do a visual of the power board caps will appear swollen on top.
The ones you are looking for are located almost center bottom of the power board,Usually I can see them clearly with the back on simply shining a light into the back through the holes. (on the Plasma Model)
look at the photo I am uploading to see what a bulging cap looks like
With the back removed you will see a few circuit boards the upper one (ac cord runs to it through a small board) is the power supply, it has alot of capacitors on it (cylindrical standing straight up, soldered in and marked on the sides with the positive/negative sides and MF and Volts values)
Philips uses 2200Mfd or 3300mfd at 35Volts rating capacitors, they cost about $1-$2 each see below for a link to matelectronics.com
usually I replace two of them (or all the bulged on top ones) .
The power board and back unscrew with a torx bit and screwdriver size 10 and 15 , if you do not know how to desolder and resolder then do not attempt this as you may damage the TV more than fix it.
We do not recommend do it yourself, but depending on your knowledge and technical ability you may be able to.
You can replace the whole power supply, but Philips has a few versions in their sets and some so called replacements won't fit due to cable location (sockets) being in a different spot.
look at the capacitors that are bulged on top and order the same ones that are in there, probably one of these
2200MFD/35V 10/for $9.50 radial capacitors linked here
3300MFD/35V 10/for $12.50
Hope this helps, if it has solved your issue please click accept and close out the request
But if you have more questions please respond and I will reply asap