First problem, the microwave does not heat, starts but with a wierd sound and a burnt smell. Service man said it probably needed a transformer or magnetron (said this without testing because the entire unit had to be removed from the wall). Parts were ordered; capacitor, magtube, transformer and diode. But now after replacing these parts the unit does not start, only gives three beeps and after he spoke with technicians at Whirlpool he determined the unit is "unrepairable" because of corrosion in the microwave tube. I'm having touble believing it's unrepairable and suspect I had a service rep with little trouble shooting experience. I've looked at several procedures and have not found any that say a certain condition makes it unrepairable. They did not charge for this service but a new combo unit is roughly $2,000.
Please advise, is it worth further repair?

Thanks Simon,
Does that mean you think it is repairable?