Just a quick shout-out (or applause) to ULS inc and Jeff.
During last year, I'd mentioned spasmodic Y axis glitches we'd had in our 2002 vintage M-300 laser, and home diagnostics identified that it was not the leads nor the stepper, but had to be in or on the motherboard somewhere.
Someone on another forum told me that Universal offer a $250 motherboard repair service, so I contacted them, and sent it off, along with the M'board to the V-460 we'd got for parts. They fixed both, (dodgy RAM connector, replaced the Y axis resistor unit, and changed the fans) and posted them back to Australia, and they arrived in the mail three days ago.
I've just put the M-300 back together and it works!
Wonderful- and thanks heaps, Jeff & ULS !