Mutoh 38 not printing yellow, please advise?

[John Thomson]

I have no experience with Mutoh printers but would suggest a pump problem, capping station seal problem or possible blockage in the ink line.

Best of luck.

john

[Fred McLean]

Engineer told me murky ink in the damper might be that it’s knacked!!
half to 3/4 full is okay but if it’s badly discoloured it might need replacing

Or as said could be the pump not sucking ink through from the carts to keep everything clean and preesurised.If you’ve got a syringe unplug the ink line from the pump to the capping station, park the heads over the station and suck through.once done try a nozzle check and see how you go!!

Might narrow down the problem, if manual sucking solves it , it probably means the pump is gone 🙁

[Barry Williams]

Hi John and Fred,
thank you for the input. I feel that the pump is ok as the other 3 inks are delivered to the heads and will print. The problem seems localised to the yellow line and damper.
Techi not arriving till next week so I will await his expertise.
I have nursed this Mutoh for many years on my own guesswork and expletives and I reckon that it would benefit from a good professional overhaul at this stage!!
Many thanks.
Regards,
Barry

[Justin Atkinson]

Hi Barry,

Normally this is caused by a blocked tube. The ink will not be able to drain away from the cap and so mixes in the cap and ink will end up going back up the head nozzles into the damper…and the strongest colour wins 🙂

Normally easily rectified with new caps and tubing and some times a pump, but I think you said the pump checked out ok. You will need to pull through a bit of ink to remove the cross contamination of inks…this will test the pump!

Hope this helps.

Justin

[Barry Williams]

Thanks Justin—
I will await the techie whose visit is promised next week and get a full m.o.t. done
on the machine
Hopefully the maintenance station replacement and new dampers will solve the problem–all of those parts I have to hand.
I’m keeping my fingers crossed that the colour head is not in need of replacement.
Again, thanks for your help.
Barry

[Barry Williams]

Hi Justin,
Printer working again. Took the yellow line off the damper and with a short piece of
old ink line fitted on the nipple above the head i managed to syphon the yellow ink back into the system—-quite a lot of air bubbles there before it showed full. Cleaned out the contaminated damper with some fluid and after assembly–mirabile visu et dictu—
it is back in production. Problem probably not permanentlly solved but should be ok till the maintenance station is replaced.
Thanks again for your hints.
Barry (hot)