Repairing a CQ50. Screen was out (very dim - no backlight). External VGA monitor looks fine, so it is not a video chip problem. Ordered new inverter, put it in, no change. Ordered new (used, from ebay) video cable, put it in, screen comes on for 2-10 seconds then goes out (dim picture still there, as before).
It does not always go out when it changes graphics modes; it sometimes goes out while still on the Compaq logo, so it is not a software problem. I figured it was a bad video cable connection. I flexed the screen and cable, pushed, pulled, wiggled all connectors on it while running, no change. Then I unplugged the video cable from the motherboard while running, plugged it back in, and the picture comes back for the same 2-10 seconds and goes out again! I can repeat this as many times as I want, so I guess it is not the cable.
Bad panel? Why would the picture look fine for a few seconds? I do not have a spare of this particular panel so I can't try a swap.
Has anybody run into this before?