Cannot get this Gotek to work!!

[Speck1965]

Ok, so brought this Gotek over a year ago, couldn't get it to work then so threw it in a cupboard and forgot about it. Anyway, recently got it out again and have it fitted to a retro PC. Still can't get it to work!
Got MS-DOS img files on a USB stick formatted to FAT32. Flash Floppy updated. Followed several other posts on here about jumpers, resetting etc, still no joy.
Upon booting, when the PC seeks the "A" drive you can see the numbers flicker, the green light comes on as if its trying to find something, but then it just says no A drive, or no boot file etc. If I manual try to view the A drive it says there isn't one.
I cannot think of what else to try, it has NEVER worked from new. Is it faulty? Any help greatly appreciated!