Need Help VS540i Missing yellow channel

[martland33]

I think I need to change the head on my VS540i and just wanted to bounce my logic off someone to confirm my thoughts please.

I've had a recurrent problem with the 'G' channel / right hand yellow channel dropping out partially and/or completely, problem has got progressively worse. Printer has been running OEM inks, parts and fluids all its life.

Initially, this had been resolved by a powerful clean, subsequently by flushing the relevant section of the head. After it occurred several times I changed the damper to no avail and have since swapped said damper with another damper in the head and the issue stays with channel 'G' and does not follow the damper. O rings at both ends of the damper were intact, moistened, don't seem to be causing the issue and can't see any cracks in the head manifold. Several other methods have also brought the channel back to life - pulling ink into the head/damper via the cap top tubes, flushing the head again, medium cleans, overnight soaking of the head and all have worked short term. Once the test print eventually comes out ok I am able to print a run and the ink doesn't drop at all during the run, whether it's 1m long or 20m long, however it all goes back to square one after a print run.

Cap top was replaced 3 months ago, a new suction pump + motor and both yellow OEM cartridges were fitted last week.

Issue to me doesn't seem to be electrical and I cannot see any air in the lines at all having inspected several times from the choke valve to the damper. All other channels are perfect on the test print and haven't been an issue during the process of fault finding.

Time for a new head?

Your time is much appreciated,

Danny.

 

[Roland Certified Tech]

Flush the complete G line from I/C needle to bottom side of head joint.

 

[martland33]

Thanking you kindly for the reply, I'll update the post as and when for anyone stumbling across it with similar problems in the future.

 

[martland33]

This in the end turned out to be an electrical issue on the print head. I turned the printer on one morning and was getting the 'temperature too high' message and the head reckoned it was at 63c. By wiggling the ribbon connector at the print head I could get the reading to return to normal, allowing print to continue temporarily albeit with partial yellow on channel G and subsequently I ordered a new set of ribbons. This resulted in a 'wrong head installed' message and when attempting to print in service mode an error code 250 (relates to fault at the head). Also when installing the problematic ribbon (2nd one in from the front), it never felt like a sound connection was being made which led me to believe it was a bad connection at the head side.
New print head was installed, ribbon felt much better when inserted and everything is back to normal after installing and calibrating new head.

 

[Roland Certified Tech]

This in the end turned out to be an electrical issue on the print head. I turned the printer on one morning and was getting the 'temperature too high' message and the head reckoned it was at 63c. By wiggling the ribbon connector at the print head I could get the reading to return to normal, allowing print to continue temporarily albeit with partial yellow on channel G and subsequently I ordered a new set of ribbons. This resulted in a 'wrong head installed' message and when attempting to print in service mode an error code 250 (relates to fault at the head). Also when installing the problematic ribbon (2nd one in from the front), it never felt like a sound connection was being made which led me to believe it was a bad connection at the head side.
New print head was installed, ribbon felt much better when inserted and everything is back to normal after installing and calibrating new head.

Thx for the update