Hi :-)
You must set these jumpers to the proper place to get something from your A3K :
J100 jumpers the other two pins than the ones you have now,
same for J104 (must be 1-2 ON)
same for J102 (must be 2-3 ON)
These jumpers are between the 68030 and Gary and FatBuster chips, on the left :-)
Your A3k should boot now :-)
Amigalement,
Jean-François.