- banding takes the form of alternate lighter and darker areas spaced around 15mm apart
- it only occurs in certain areas of continuous midtone, and only with certain colours. So far I've only been able to reproduce the effect in large areas of dark-coloured sky... but not all skies are affected
- the banding is inconsistent. I can print the same image twice without changing any settings or doing anything to the printer, with one print showing the banding quite badly and the other almost (but not quite) unaffected
- most images remain unaffected
- the nozzle check consistently performs perfectly, even under close scrutiny
- printing a grey/rgb/cmyk purge image reveals no banding
And this is what I've tried, so far to no avail, to fix the problem:
- checking the paper thickness setting (it's set with the print head on the lower setting)
- testing and tweaking the head alignment
- windolene cleaning of the underside of the print head (but only for around 10 minutes), followed by a clean cycle and purge printing
- uninstalling and reinstalling the printer driver
- trying a different USB port on the computer (clutching at straws, I know!)
- cleaning and then lubing with a _very_ small amount of WD40 on a cotton bud the print head carriage bar (I've not read about this anywhere, but I did have an Epson printer that developed bad head judder and needed frequent lubing to keep it from jamming. And I'd like to stress I was extremely conservative with the WD40...)
None of this seems to have had any effect. I'm still left with a printer that produces perfect results with most images, but then throws me the occasional curve ball. The only discernible patttern is that the prints most prone to banding tend to have large areas of continuous tone... but then again while it's been misbehaving I've also printed a couple of images that fit that description that turned out fine.
Needless to say, the unpredictablility in particular of this problem is driving me slowly mad. Suggestions are very welcome. The only things I can think of that I haven't tried yet are to swap the USB cable and to do a careful overnight Windolene clean (which I'm trying now).
(Oh, and I've also discovered some subtle vertical banding in one or two prints, up in the top left (portrait) / lower left (landscape) corners. It's definitely not anything to do with the file - I reversed it and printed again, only for the banding to stay in the same place. Any clues?)
Thanks in advance.
Best
Seb Rogers
=============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
