Beat me to it (hate mobile keyboards!} but concur completely, with the additional thought that loose wire might be in the socket, so try new plug in different socket first to verify machine's OK, then try on suspect socket... or just have sparky who fits plug check the socket
I reckon plug though, especially if you often plug/unplug it; the repeated cable movement would do it.
I'm surprised it even worked with a 3A fuse, current drawn is much higher for tumble driers.