Panasonic JU 253 troubleshooting help needed

[gkmaia]

Hi, I got a Panasonic JU 253A drive that is not being able to read or write data.

It spins, head moves, mechanically is seems to be all operational. But the logic side is not.

I've attached a bunch of scans of the main signals sent from and to the drive. Also the service manual for the 253/257 series.

I just would like to ask if any of you see any signal that do not seem right. Or based on the signals if we can pin point the issue to heads, controller, etc...