First item,,
I've seen lots of 800/810s with lube on the leadscrew from the factory.
Two, carb cleaner is toxic and usually bad for most plastics.
My cut is pull the lead screw/stepper and properly clean it and lube
very lightly with good molly grease.
that is available to you, then lubing it with a LIGHT
coat of (one drop for
every three drives) of WD40, then adding about 1/4 tsp of moly-disulfide,
WD40 is penetrant and evaporates very quicly leaving mostly nothing.
After your done cleaning any know good disk will suffice for alignment.
I've even eyeballed them in. the tracks are really quite wide!
Allison