At one point my Blizzard 1260 died. It turned out to be the oscillator, of all things. I socketed it after that. If you have to try a few things via trial-and-error, you might as well try the simpler things first.
Other things to check are voltages (either the power supply might not put out enough power or there might be a bad connection somewhere), dirty contacts on the accelerator slot and the condition of the SIMM slot on the Blizzard 1260.
How long ago did it last work? Did it ever work in the system you're trying to use it in now?