Obviously if you have a new belt and you've tried it .. (you should try it even if it looks the same) ... then I don't need it.
I am still using the original belt on mine (now at 4600 miles) .. it even has a 'burned' spot .. (like they sat in one spot with the pulley spinning against the belt ... for a long time)
Still using it .. seems fine to me.
You can pop the belts on and off without any other disassembly .. (cept removing the belt cover).