A3000 tower jumpers for a3640 should be
j100 3-4
j102 2-3
j103 1-2
j104 2-3
j105 2-3
j106 2-3
j107 2-3
If jumpers are set for a3640, or cyberstorm the on board processor will not boot with accelerator unplugged. I would highly recommend you do not ever change J105, j106, j107. Things can be ruined. :-o