Hmmm.. First of all is the A3k a 25 or a 16 mhz.
If its a 25mhz then don't bother with the A3640.
My A3k is a 25mhz and I added the A3640 card.
The A3640 runs at 25mhz. There is a little gain
from the card but not that much to bother with.
As for the 16mhz machine, the A3640 card helps
quite a bit. The a3640 card in a 16mhz is worth
while.
I glued a large HeatSink to the 040 chip and mine
hasn't given me any trouble. Its stable.
And when installing the A3640 card in an A3k,
first make sure its the correct version, and
the correct roms and get the correct jumper
settings.
The A3640 card won't work with Version 37 roms.
Its best with 3.1 roms.
Blow the dust out of the machine and clean the
fan in the power supply.
Mel Ott