make sure the bridges are installed the correct way, could also possibly be A shorted varistor VR1?
You could try removing all of the other fuses except F6 and see if it still blows, if it does blow F6 without the other fuses installed, it could be shorted wiring between the transformer and the PCB, or worse case scenario.. shorted windings the the transformer itsself.
If the F6 fuse does not blow with the others removed, you could try reinstalling each fuse, one at at time until you come to the one which creates the fault,
oh.. and have J3 removed as well while testing!
hope this helps!!
Cheers... Mitch
