M107 dont shut down pin 2.4

hi all,
im building a super rigid delta, everything seems fine but today i have a problem:
the output for the fan pin 2.4 remains always open. it worked for few seconds with a test fan connected then caput :frowning:

i restored an old config but the mosfet wont shut down.
can be the pin somehow damaged? how can i troubleshoot the problem?
many thanks in advance

Imported from wikidot

Did you install a diode on the output ?

If not, the fan probably killed the mosfet.