WT7900 proofer - clogged yellow - can't get rid of it. Any fixes? Any alternatives?

[prepress labels]

Hello!

Our Epson WT7900 proofer (six years old this month) is clogging in about 1/3 of the yellow nozzles, and no amount of cleaning/power cleaning/physical cleaning has fixed it so far. Here's what we've done:
1. Run cleanings or power cleanings: these usually result in a "Cleaning Error: Retry?" message.
2. Replace the low yellow cartridge. Didn't help.
3. Open the door to the proofer, go into service mode to free up the print head so it slides freely, & clean out the flushing box, underneath the print head, etc., with paper towels & isopropyl alcohol (following a video on YouTube). Didn't help with the yellow (we did get a lot of ink cleaned out though).

We know this proofer is way past its support, and I've seen postings of similar issues before. We've also upgraded to a new Epson and use it for our white substrate proofs, only using the WT7900 for white ink on clear, varnish overlays & the like. All other colors except yellow are working fine at the moment.

Does anyone have any further ideas we can try? The white ink itself is still functional, but when that goes, we won't be able to produce true white-ink proofs anymore. We're worried that the yellow might be the "canary in the coal mine," and that the day is coming when the white gives out permanently.

If we can't fix it, what alternatives are there? We've brainstormed:
1. Buy another used WT7900: it may come with the same mileage and/or print issues we have now.
2. Look for a new proofer that produces true white ink: we've only found one option, for about $50,000.

Any other options? Thanks for any input!

 

[gordo]

Would a sonic cleaner be a viable method? I’used this method to clean extremely small nozzles on technical drawing pens. Here's a video of a sonic cleaner being used on a desktop printer: https://www.youtube.com/watch?v=2IqtsMRlSqI

 

[prepress labels]

Would a sonic cleaner be a viable method? I’used this method to clean extremely small nozzles on technical drawing pens. Here's a video of a sonic cleaner being used on a desktop printer: https://www.youtube.com/watch?v=2IqtsMRlSqI

Gordo,

Thanks for the suggestion--it might be possible, but I've never removed a print head completely, and I probably wouldn't unless the proofer was really going out of whack. I'm not even sure that the print head would fit in the cleaner (haven't really researched sonic cleaners before).

Here's a video I used to do the cleaning I did: https://www.youtube.com/watch?v=m8NkgKw7mDw
I might try it again, but I really got to a point where not much ink was coming off onto the paper towels. It just isn't working on the yellow for some reason.

 

[schenkadere]

I did this with my 7900 and it worked https://youtu.be/lU6PbizbKaw Didn't work for my 9900 but it's worth a try. Doesn't cost anything.

 

[prepress labels]

I did this with my 7900 and it worked https://youtu.be/lU6PbizbKaw Didn't work for my 9900 but it's worth a try. Doesn't cost anything.

I took a look at that video--I may try that. Thanks!

 

[prepress labels]

Update--just tried it and still the same thing with the yellow--it's a big chunk of nozzles in the middle (the Epson prints a small line for each nozzle, in a rectangular shape).