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At least these older things use much bigger SMT than is out there today. On my bench for board reworking I keep tweezers, jeweler's screwdrivers, desoldering bulb, and 30 AWG wire for jumpering. Also a bright directional lamp. As I am getting older I should probably get a positionable magnifier also. Also I avoid jitter, like caffeine and stress, before tackling fiddly bits.
Sounds like you found the cause of the problem. Same thing happened with an 8100 I found - it worked fine when I found it. It started to flake and when I took it apart for troubleshooting, parts, caps mostly, started falling off of the video card. I suspect that some of these things can pick up a lot of moisture which causes them to corrode and fail. Bad solder could be an issue also.I lifted the Quadra up for a better angle in the light to see if there was any dirt in the RAM slot, and one of the capacitors just fell off. The pad was completely corroded. :O When I had it plugged in, I smelled the unmistakable sweet stench of frying electrolytic goop, I figured it might be a bad capacitor. At least this saves me time figuring out which one.
Fortunately I happen to have quite a few of the same kind, the 4uf 16v surface can from when I was attempting to recap a bad LC board. Unfortunately, I have the worst luck with trying to solder surface mount resistors and capacitors.
At least these older things use much bigger SMT than is out there today. On my bench for board reworking I keep tweezers, jeweler's screwdrivers, desoldering bulb, and 30 AWG wire for jumpering. Also a bright directional lamp. As I am getting older I should probably get a positionable magnifier also. Also I avoid jitter, like caffeine and stress, before tackling fiddly bits.