Humidity causes Asko clothes washer to buzz and not start
I also have an elderly 20004 excellence that screeches and won't start when humidity is high; a damp laundry room in winter is the problem in my case. Whenever the repair man attended it behaved perfectly. 

I decided to investigate the electronic circuit board as that is where the singing seemed to be coming from and found that there is very little protection for this board from the big space surrounding the drum and all those suds. The board had some yellowy brown substance on it (probably detergent residue from an oversuds adventure in the past)  which I carefully and very gently cleaned off with rubbing alcohol, some paper towel and q-tips using a rolling movement so as to minimize damage to the pins and  delicate surface. Be careful not to leave any paper or cotton "crumbs" caught on the sharp bits.  I was amazed at how much dirt was removed and how the washer was instantly fixed.

I have repeated this every winter for the last few years whenever the circuit board sings and have been grateful that the tiny cost of one special screw driver and a gentle clean could prolong the useful life of my washer.

Hope you find a solution for yours.