I have a Florabest Long Reach Electric pole pruner

I have a Florabest Long Reach Electric pole pruner model no FHEHS A1, Bought from Lidl 4 years ago, so out of warranty, I used it the other day with the Chain Saw attachment on it, it made a buzzing noise and them started to smell, after that I can’t release the safety catch to try it again, any thoughts?