Actually, the good news is that your television is fine. (exhale!)
The set is set in "Shop Mode", which reverts the television back to default settings usually after 20 minutes, or after starting the television.
There are one of two ways to fix this:
1. Hold down the menu button for about 15 second. The screen might flash or display "Dynamic". You will have successfully turned off Shop Mode.
2. On some panels, you have to push the volume button up once, and then let go, and hold down the Menu button for 15 seconds. (Basically, hit the volume button once and repeat step 1)
Keep me posted.
I have just had the PCB changed on my Series 6 LCD and at the same time they updated the software (assuming as it was last week it would be latest).
Now the picture keeps reverting to dynamic mode even after I change to standadrd. It also reverts to the 100 mghtz when I turn it off.
This happens after about 3 minutes whilst tv is on. Screen goes black for 3 seconds and then picture reappears with factory settings.
Any ideas or do I call service centre again?