Phillips hdtv 42PF7220A/37

Most of the reported symptoms like these are power supply related and not usually an expensive repair.. If you're doing this yourself take a look at the power supply board - you'll have to remove it - check the cap at 2662 for any signs of buldging. If you have an ESR meter measure it's equivilent series resistance and replace if necessary. Next look closely at the board for ring cracks of the various solder joints. Pay close attention to the diodes at 6041 and 6046. part of the bridge system. Any ring cracks found flow some solder across them to make good contact then re-install the power supple and try to power the unit.
Bill