Looks like it was corrossion on the ribbon connector or another connector,
the rest is probably RTFM.

Supercap is connected to p51 and p54 of the 64 pinner so probably retains
memory for a maximum of 10 minutes of power outage.
Then from the manual there is a "Resting" stage where the heater comes on
for a second twice a minute unless you warm the bucket temp sensor with hot
air. Similarly selecting "Dough" the oven has to be up to some temperature
something like 25 deg C before the motor/kneding action starts.