I have a Roland XR-640 that all of a sudden head a has lost two colors totally. I haven't had any head strikes and the machine is taken care of meticulously. Only Roland brand ink. So trouble shooting this myself I have replace the dampers and caps, Roland original parts. While looking at the lines I noticed that one of the lines for a color I lost has an air bubble in it. So I tried to pull ink through the head using a syringe on one of the cap drain lines. I hear a gargling sound like the cap isn't sealing to the head and I can only pull air. I see no ink flow through the lines either before or after the head. I tried the other cap for the other head and it also has a gargling sound and no ink flow in the lines. The original Roland caps that I used are a few years old, not sure if the rubber goes bad sitting in the package that I found that were given to me when I bought the machine. Also machine is only 2.5 years old and not run that heavy.
Does anyone have any idea on why the caps are not sealing to the head correctly.
With all you stated you never stated which boards and which cables.
All four print cables and the two main print boards I was told.
A few questions. Which 2 colors are you missing? Both colors on the same head, one color on each head?
Post your test print.
I maintain over 50 XR machines for a few customers, and I've never seen this issue ever be a board problem.
The fuses provide power to the heads. Fuse one is overall power, fuse 2 is head A and fuse 3 is head B. It's all or nothing, not all colors but one or two.
You cannot syringe ink through the cap top without blocking the other line on the captop. Pull both lines off the pump, block one and attach your syringe to the other.