I had this model of accelerator, new, and had the same problems as you and the cause was it would overheat. I put a heat sink on the cpu, and I bought some rubber feet to lift the A1200 and ran it without the trapdoor cover. It helped, but not in 35+ C degrees. In the end I sold it.
If you can get a fan for it it may do the trick.
Acclerator recommendations. The Blizzard cards seem to be reliable and can be disabled with a key stroke.
I ran an Apollo 1240 for years without a prblem though, until it yellow screened, was repaired by PG due to a fried CPU and is now a 1260 running at 40 mhz (not 50 mhz), but never crashes.
