This machine has served us well for the last ten years but has now
developed a fault.

When you start it the display reads 88 minutes, and all is well until
about 40 minutes when it suddenly goes to 0 and the machine stops. So it
never completes the cycle and leaves the contents dirty.

I suspect it is the control module which is faulty, in which case it's
probably a write off, but is there anything else that could cause this?

Nick