The Natural Philosopher wrote
Rod Speed wrote
Lieutenant Scott wrote
Andrew Gabriel wrote
Adam Funk wrote

On a related note, is there a good & easy way to destroy data
CDs? The shredders I've come across with CD slots just scratch
the surfaces up a bit rather than break them into bits.

I had a large pile, and didn't like the idea of feeding them all through the microwave, in case it damaged it.

Does anyone know if you can bust a microwave if there is nothing (or not much to absorb like water) in it?

In theory you can, but decent modern designs allow for that.

Corse all bets are off with the cheapest **** from china.

even the cheapest **** from, china has to be essentially protected against anything a consumer can put in it because
at some point a consumer will..

Nope. Just like with the earliest locally manufactured microwave ovens, they
just accept the fact they they will die, because thats a cheaper approach.

And if you try to claim in the warranty, they rub your nose
in the bit of the instructions that say you shouldnt do that.

Will it overheat as there's several hundred watts of microwaves
with nowhere to go but the dummy load in the magnetron?

Normally not.

Not sure if there is no 'load' the magnetron will draw much power at all.

That did happen a bit with some of the earliest microwave ovens.