WMA62 aborts all programs after 2 initial spins

Hi, Very recently my WMA62 (not 64 but it's very similar I think) stopped in the spin cycle. I opened the machine cover and saw that the belt was loose. This is a 4.5 year old machine and not heavily used. I replaced the belt with a new one, still no joy. Then I checked the brushes on the motor and they seem fine, plenty of carbon left and no obvious damage. The motor looks almost brand new. In my opinion, the problem seems to be that the machine thinks it's unbalanced. I think this is what happened with the original wash, I had some heavy items and stopped. I've tried spinning only programs. It starts ok, attempts to spin twice and after 1 min aborts the program and switches off. I've also tried starting a normal cotton/ handwash program, in fact almost all available programs! but still the same, it tries to spin fast (even at the cotton program) then it tries once more and switches off. In my opinion there is nothing wrong with the balancing. I've made sure it's balanced (with a spirit level as well) and I've tried with no clothes and I can see the drum doesn?t shake at all from the outside. I think for some reason it's stuck in an unbalanced state and can't see that it's balanced now. This is the reason it attempts a very quick spin at the beginning of a normal wash cycle. Can you reset it somehow? Does anyone have any other ideas? Thanks alot.