There are two places you could try.
The first is right behind Costigan's Bar on Washington St. That bar is about 30 metres past the Courthouse, on your left, as you head towards UCC. The place in question (can't remember the name of it) is beside the back door of the pub on Hanover St. They repair appliances. Their phone number is 4273579.
The other place is Greg Lane's in the Woollen Mills in Douglas. His number is 4891716. He does vacuum cleaner repairs and may be able to sort you out also.