Originally Posted by db100
... The actual reason is the light (probably UV light) causes the charges to be discharged. That means, screen is defective.
Send back to store (if still within 30 day return period) or SONY, they can either replace or repair it for you.
Thanks much for this info as to the actual reason. So despite the 135 deg. operating temps, seems I have a fader. Will take your advice and return under my extended warranty from Sony.