There is a small board with the intake motor on it. On 1200s and Slims, it's called KLD-00X. I forget what it's called on a Pro. but they're all interchangeable. Anyways, there's a few switch on that board. If it's taking the disc all the way in, but not spinning, I'd wager that one of the switches on this board is not functions. Or the ribbon going to this board or to the spindle motor is damaged.
If none of these turn out to be malfunctioning, then you can replace the entire laser assembly (or drive if you don't mind spending extra).
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