I've recently acquired a very nice SE/30 with a great looking Logic board

I decided to wait with my conquest topic about it until I recapped the logic board.

Did successfully wash the board, did replace all the smaller caps while still leaving the two bigger caps in place, without one ripped or lifted pad

Now everything works... but one thing, the floppy drive.

It does read sometimes, it does write sometimes, but...

If I try to initialize a 800K disk it just says "initialization failed".

If I try to initialize a HD 1.44MB disk it gives me a bomb with sometimes a visible error about 'A math coprocessor not' being 'installed' or 'Address error'...

Now i know the Bourns-networks are vulnerable on these machines, is there a way I can test them without de-soldering?

I see no corroded vias, corroded chip-legs, solder blobs, pieces of metal or any other dirt on the board.

Am I missing something? Am I too stubborn by leaving the 220uf and 470uf caps in place instead of also just replacing them?

Would be fantastic if you could point me in the right direction!