More likely worn out carbon brushes and possibly a blown main board.
Check the brushes first, if worn out, you'll need a new set.
Check the main board too, see if it's blown.
It's not uncommon for the brushes to wear down, arcing then occurs at the motor and if allowed to run like this, the board blown.
See what you find, get back to me if you need more help.
Hope this helps
Thanks, I've found genuine Siemens brushes for £30 which I've taken a gamble on and ordered. Main board hopefully OK as machine appears fully functional apart from drum rotation.
I'll get back to you or rate if sorted. Thanks so far.
Did you check the existing carbon brushes first?
If they aren't worn out then new ones won't make any difference.
Even though the board is fully functional, apart from motor action, it can still be burned out on that circuit.
Normally, you can see the damage if you take the board out.
Good luck with the repair.