Sharp Twin Famicom - Won't load disks, no error code

I've got a Sharp Twin Famicom that won't read disks. It never shows any error numbers, just continually says "Now Loading". Famicom cartridges work fine however.

I've tried:
Replacing the belt
calibrating the spindle
adjusting/cleaning the head
cleaning/greasing the rails and sliders
replacing the belt/calibrating the spindle again
Check continuity from the r/w head to the board

Still get the exact same issues. Oddly enough, once while testing it, I failed to plug in the r/w head, and continued to get the same issues - Can a head go bad?

I'm completely out of ideas to test, short of getting another FDS and swapping the drives.

Any ideas? Has anybody experienced this issue?

 

Heads can go bad on floppy drives. What does the head do when it just says "Now Loading"? Does it keep seeking? Does it stop?

 

It just keeps going. Keeps seeking ,the head moves back and forth, doesn't seem to stop (i let it go for 10 minutes), doesn't produce an error or anything else. I've ordered a regular FDS with ram adapter, so I'm going to try test that drive in my Sharp to make sure the issue is just restricted to the drive, but I'd like to figure out what it is if possible. If the head has failed, well, not much can be done I guess.

 

Yup, I'd be willing to bet that it's a failed head. As a hail Mary, have you followed the head adjustment guide at the bottom of this page?

http://www.famicomdisksystem.com/tutorials/fds-repair-mod/belt-replacement-adjustment/

 

I've seen this caused by bad electronics in the drive - either the read amp or the write circuit being stuck on. Note that in the latter case it will also trash every disk you feed into it...

 

I'm looking for a Sharp Twin Famicom board if you give up. I'm not planning on using real disks on it. Mine has a ppu or videoram error, beyond my fixing talent.