SE/30 only reads write protected floppies

[Bolle]

That's what I mean when saying it might be shorted internally.

The other possibility is that the short is coming form the SWIM itself.

Without removing either the filter or the SWIM you won't find out which one is to blame though.

 

[macclassic]

FIXED

Many thanks for all the help as this fault was caused by was a shorting Bournes filter at RP10, but I also enjoyed checking all the traces from the SWIM chip and using a heat gun for the first time.  :