Leon,
Sorry to hear that! I take it you've given it a complete power cycle?
Is it a problem in RA or DEC?
I only just refitted a new gearbox to my declination axis tonight. I noted that the gear was rather stuck when it came out of the packaging. I had to apply quite a bit of force to get it to spin. Dad said it was probably just the grease that needed a bit of budging. Maybe I should have waited until after IISAC. I'd hate to go up there and find that I've got no guidance in declination!
Whatever it is, I hope you get it sorted.
Regards,
Humayun