Staighteners dead?

My new pair my mum bought have also gone dead. Another answer suggests thermal fuse problem may be cause. Says to unscrew cover on switch & led side. A friend who repairs electrical items wonders if you know hoew to get at small scre near the hinge. He has tried all ways but failed to be able to part at hinge. Please help me if you can, my mum is a single mum. thankyou.