total disaster after teardown
After reassembly (reason being, another machine appeared to be destroyed by a power outage - was attempting to swap PSU) all the video I can get is a fuzzy flashing magenta/gray for a second or two.
It's booting up OK (can just see apple) but I think I've wrecked something. Help?
First step - recheck all connectors. Sometimes they "seem correct" but on second go 'round it turns out they are not square, fully snapped or locked in… ribbon cables fully inserted with cams open, then locked.
Pins may be bent or damaged… look for burn spots around the GPU (if you pulled the "good" PSU to put on the "surge damaged" logic board)…
If this answer is acceptable please remember to return and mark it.