Roland VS-540 - Only Magenta Printing test, other colors missing. (Photo Included)

[Alex C]

Hi everyone,
I'm working on a Roland Vs-540 and running into an issue I haven't seen before. When doing a test print, i'm getting only two magenta channels printing - No Cyan, yellow or black at all.

Here's what i've tried so far:

- Replaced print head No change.
- Replaced Head Cables No Change.
- New dampers installed
- New Captop installed
Confirmed ink presence - cyan, yellow and black are visible under the head and even on captop.
- Mainboard fuses tested and OK

Here's a photo of the test print output:

I'm starting to think this may be an electronic issue - possibly the mainboard's firing transistors or IC's for the non-magenta channels. Has anyone seen something similar or can suggest a next step?


Appreciate any advice

Thanks in advance


AleX

 

[Zoogee World]

2 things I might suggest, 1. Did you test the big transistors on the head to see if they are all good? 2. Did you try pulling ink through the head with a syringe attached to the line after the cap top?