I have replaced both the motor and thermostat and that did not help. I did not have the tool to check circut board but visually all looked fine. At least now after 10 times of disaassembky I know how to do it. I will check the capacitors again. The official info about contacting electric supply company is absolutely out of the question. I have tried different networks and sockets.

My recommendation for step 4.

Do not leave the compound to dry completely. When it is getting dry, but still a little wet, use a wet sponge to smooth the compound. That will save you a lot of work with sanding.