Ok Just re-belted a twin famicom. Head adjustment screw is still covered in the red loctite type stuff and I have not touched the hex bolt to rotated the spindle so this should still be 100% factory. I get error 22 on all my 3 disks. I really fear moving even the spindle since in theory the factory settings should be good since I marked everything before disassembly. That and I have fought my famicom disk system for nearly a year now with error 21 and 22s. Thoughts?
Changing the belt always results in the spindle factory alignment being lost, as it's based on the relative position of the wheel. You *have* to adjust the spindle.
The head itself I would not touch.