Thanks all, for the reassurance!
It's true that I have little to lose, since I can't find anybody who knows what they're doing to fix it, so the alternatives are get a new one (seems drastic, since this one is only 3 years old) or let somebody who doesn't know what they're doing fix it - which might as well be me.
It's been broken for awhile, and I've just been using drying racks by my wood stove, which works fine and is more frugal, but I do want it to get fixed eventually.
It is a ventless condensing dryer. I don't think this will make it more complicated to disassemble or repair - it does mean that it needs to be disconnected from the washer's drain pipe (that's how the condenser drains the removed moisture), but that's very simple.
I did find the exploded-view and wiring diagrams online, but no directly-relevant youtube videos for this particular dryer.
I'll get the part and report back on the I-hope-successful mission.