The Daewoo microwave packed up in our 07 Senator a couple of weeks ago. It went through all the motions, light on, turntable turning and making the correct sound but it no longer heated anything. It would not even melt butter.
Bought a new microwave from Tesco for £32 and replaced the Daewoo. The old microwave is held in by two screws underneath. The piece of wood above the microwave needs to be removed - held in by four screws into the side. Remove the old microwave. It has a piece of wood screwed to it's underside to raise it's level in the compartment and this is also where the two screws underneath fix to.
I fitted the piece of wood to the new microwave, put it back in the compartment, made sure the door would open properly and fixed the two screws back underneath. I then fitted the piece of wood back above the microwave, which meant lowering it a bit and job done
HTH.
Graeme.