Fixing a H02 error on a Panasonic DVD-S35
This image shows how the drive is situated very high in the case.

If there is something resting on the top of the case, it can eventually deform and cause the drive to stick. Remove the case's top by removing the three screws in the back plus one each side. Load a DVD into the drive, and then during the (failing) spin-up, gently push the white circle in a clockwise direction.

The drive should begin to spin almost immediately and work properly from there, even after the cover is replaced.
(Worked for me; your mileage may vary.)
Of course it goes without saying that you should refrain from putting heavy things on top of the unit when it is returned to the stack. In my case having a PVR sitting on top of it (off-center because of where the A/V case doors and the individual device's I/R remote listener locations were) for over a year caused the drive to eventually stick.