I have a 37in, the screen keep going blank for a bout 5 seconds and when it comes back on the constrast goes up to 100

This is a combination of the backlight inverter and the mainboard. It is going into fail safe mode when the backlight is failing and resetting to default settings. I believe once you change out the backlight inverter that your problem will be solved. Also, check for popped capacitors on the powersupply to make sure that the backlight inverter is getting the 24v it needs to operate properly.


Please rate if this helped :)