Panasonic JU-253-143P broken or not?

[zyonee]

Hi, people.

I've bought a pre-owned Panasonic JU-253-143P drive. It's an 880 kB drive that has been taken from an external drive housing. Despite not fitting neatly inside an Amiga 1200, I've connected it to the motherboard of my C= Amiga 1200 (not the AT version) and what happens is that it detects there's a disk, starts spinning and does the typical loading tick sound twice, then goes back to the boot screen. This is with any disk, DOS or non-DOS. I've checked the jumpers, they're set to 0, MD and RY. Is this a configuration problem or is the drive broken? The seller said it has recently worked in his external drive housing.