WS2 crashes dispensing coins

Hey,
I have a wash select 2 that crashes when it has to give change. If I unplug then replug the hopper cable to the main cup board it will work for a few days then go back to crashing. The harness is new
And all the set screws in the green block are good.

any ideas what it could be other than having to throw a spare cpu board in there?

cheers

Turns out its not tied to change dispensing. it appears to crash now after triggering a wash relay