Samsung PS-42Q96HD

[bilsat]

I have inherited a Samsung PS-42Q96HD with a faulty PSU.
 I have replaced several caps and it's now working ok.
Only fault I have now is that  when I set the colours, Brightness all well for up to 30 mins then the picture goes blank for a moment and all setting revert to factory defaults, this then stays until you manually set them again and it repeats itself.
Years ago Philips TVs has a similar fault due to a defective eeprom, or is there a software update?
Pete