Do you have a Sony or Philips recorder connected to the Q-link scart socket? As this can cause that model to randomly switch to standby. There's a modification to stop the problem - see a Panasonic dealer.
Also, try turning up the contrast and brightness during a bright scene to see if it causes the set to trip off. Maybe the protection circuit is activating during high beam current. If so, take it back to repair shop with that info.
Cobweb
July 2007