Just received a very nice F3 through ebay today. Body is super clean. Shutter speeds seems to work great through all speeds, but when I put it in Auto, the meter in the viewfinder shows -8 and when I fire the shutter, it stays open and mirror locked up. I then have to flip it over to 2000/sec to bring the mirror back down. The weird thing is that when I open the film back, the auto mode will work for a few frames, but then revert to same problem after that. Very strange.

If it doesn't look like a simple fix, I'll try and send back to seller since the listing said all functions work perfectly and could just use new seals.

Anybody have a clue on this? Thanks.