So, after 11 months of printing using my (used) Epson 7900 I've hit a nozzle clog I can't clear. See the picture, it affects the black channel only.
When the issue began, a nozzle check would appear clear, but as soon as I started printing an image, the same nozzles in the black channel would clog. I would clean those nozzles, restore a clear nozzle check, and start printing again, only for the issue to immediately return.
After repeating this cycle about 5 times, the I stopped getting a clear nozzle check after the cleaning cycles and the patch of PK nozzles stayed clogged permanently.
Since then I've tired the following steps to resolve the issue.
- Paired Cleaning Cycles (Normal and Powerful)
- Normal Cleaning cycles
- Powerful cleaning cycles in service mode
- Power Cleaning
- Switching from Photo to Matte Black, and back
- Cleaning the capping station, flushing box and wiper blade
- Windex style paper towel print head cleaning (overnight)
- Moving the print-head back and forth over Windex paper towels in an attempt to brush any debris off the print-head
Based on this field repair guide:
http://www.scribd.com/doc/91839121/EPSON-Pro-7900-and-9900-Field-Repair-Guide#scribd, I wonder if the problem could be damper related but am not sure.
Intuitively I think something could be stuck to the print head, but I've no way to check.
I'm really not sure what to do next so any advice would be much appreciated.
Thank you in advance,
Tom