Philips 42PF7220A/37 April 2006. Chassis Number...

Question

I have a Philips 42PF7220A/37 April 2006. Chassis Number BP2.3U TV that does not work. The front LED flashes red seven times and the power supply led flashes green three times. VSCAN voltage drops to zero (or climbs). I unplugged the power feed cable to the y-sustain board and the error codes go away and VSCAN voltage remains at -190VDC. I replaced the y-sustain board and the error codes went away for approximately 30 minutes only to return again. I still did not have a picture for that 30 minutes