The build spec sheet online and the properties in device manager show the card is an NVIDIA GTX 285M... not my area of expertise but I double check before asking questions. The strobe effect will sometimes happen right away on bootup and other times just about anything media related can trigger it. A video, adjusting the volume, a click of the mouse or even "a blink of an eyelash" (hair trigger).
I got a heat sensor app installed called HWinFO64. It shows the GPU temp range as 48-51 deg C and the current (~7 min of operation, at least 3 of which were lo-o-o-ng startup) temp is 50 deg C.
GPU (HW) temp range shows 50.3 - 53.7 deg C and the current (HW) temp is 52.7 deg C
I am wondering if there is a loose connection or possibly some corrosion "plaque" affecting the connection. I worked avionics in the Air Force but am not a PC tech by any stretch of imagination. Just a retired guy on a limited budget trying to get my once in a lifetime powerhouse PC find up to its potential without missing any meals.