ASK200 Dye-sub: banding on prints

The ASK2000 (from Fuji)that I have has been serving me well for the last year,

with one exception. Sometimes in the mid-tone regions (out of focus backgrounds,

or faces) it produces prints with a subtle but noticeable banding, running in

the same direction as the ribbon and paper rolls.

Unless you look closely you might not see it, but having spotted it...

I've had conflicting reports from Fuji UK. Their technical guy yesterday told me

that the printer in their service lab definitely didn't do it (with my test

images.) Today the sales manager told me that every model they'd tested did it

and the only solution they could come up with was a full refund. (Actually he

did the salesman thing of using a lot of words to say nothing at all, by which I

understand that Fuji UK don't have a clue if other printers do it or if it's

just that there's a fault with this one - they want only to buy their way out of

the problem.)

Does anyone else have one of these and could they run a couple of test prints

for me? Or is it generic dye-sub issue? The bands appear to be related in

spacing and appearance to some corrugations in the ribbon roll as it's spooled.

I'd suggest a media fault, but every roll I've used (some 10's, from different

batches) has had this.

Has anyone anything to suggest? Other than this problem the printer is just what

I need, but it's annoying to have certain prints that come out sub-standard.

Some dye-sub printers have banding in certain circumstances. Clear blue sky is a prime example - fairly dense pigment and no detail to obscure the process.

You might try cleaning the heating element. Follow the manufacturer's instructions. Don't use solvents unless approved. Also clean the rollers. Uneven motion can cause variations in print density or actually scuff the print.