Red, do you have the key? Ifso, is the switch set to unlocked? It should, otherwise the machine will not work. Also, be sure to check the cable (blue) from the key to the motherboard, they tend to come loose. Same thing, cable not connected, non working amiga.
The jumpers for a 3640 are indeed different then for the onboard 030, check amiga.resource.cx for a picture of the motherboard, set the jumpers identical and it should work.
I just got another 3000T-040 which also didn't work, but troubleshooting it was a little more difficult because it has no 030 onboard. Finally got her running setting the jumpers to INT and using a GVP TRex board.
Good luck, she is one of the most worthy machines to get working again!