VG-640 strange test print, any ideas?

[emhmotorsports]

Hi everyone. I'm seeing some strange stuff on my VG-640; it seems to be printing Cyan where Magenta should be (also happens to a lesser extent with Light Black and White). I've attached a photo of the series of test prints that I ran. I also seem to have a bunch of dot drop outs, but not consistent across the test prints. I'll also mention that the Cyan head has begun weeping pretty badly. Any ideas on what might be going on?

To try to resolve the weeping issue, I've done about a dozen damper fills to this point. All four heads and dampers were replaced a bit over a month ago, and the machine was printing in spades until about the last week or so. I started noticing more and more ink being left on the media clamps in the morning. Performed a super clean as well. The test prints still come out just as terrible and cyan is weeping pretty badly still. When printing magenta, I can actually see it lay down the cyan first. I'm reasonably confident that the ink system is pretty (air) tight, I've gone over all the connections except for the pumps (internal), so I might throw my spare head on the C/M and see if that fixes the weeping. But as for mixed up dot colors, could this be a main board issue?

 

[Zoogee World]

How old are your cap tops, if they weren't replaced along with the heads and dampers, I'd do that first.

 

[emhmotorsports]

Thanks for the reply! Yes, cap tops were replaced at same time, though I'm not sure they're Roland parts. I've got a set of new Roland ones coming and will give that a try since it's relatively inexpensive to do.

 

[Zoogee World]

I've had similar issues on my SP-300V's and usually it's the cap tops, however I have on occasion had to replace the dampers as the inks from one channel would go into the other and cause the mixing, so you can always check that, but if you are having cross contamination on the same head, it could be an issue with the head itself, but let's hope it's a simpler and cheaper solution.

 

[emhmotorsports]

Sorry for the bit of delay, it took a bit to get new parts in. I decided to try replacing the damper for the C/M head. As soon as I removed the head and got it on the bench, I could see there was quite a bit of mixing of cyan into the magenta side of the damper. After separating the damper from the head, it was more visible. I cleaned up the head really well with some solution, applied a bit of solution to the damper seals, and reassembled. After a couple damper fills, ran a test print and the issue I was seeing with cyan weeping on my media clamps along with contamination into the magenta was totally gone! The Lk/W head is still bleeding over into white and is weeping a bit as well, but I'm quite confident now a damper change will solve that as well. Very happy this wasn't an expensive or time consuming thing to solve.

These dampers have probably a couple dozen hours of printing on them - a bit concerning to have issues so quickly, but I'll keep monitoring the situation after changing out all the dampers. I'll have to clean up this "bad" damper and take a closer look, but at the moment it seems the cellophane (or whatever that clear plastic is) weld/glue has a couple of failures at the very bottom (closest to the head) on both sides. This would certainly explain why the system was acting as if there was an air leak in the ink circuit anyway. I'm also highly suspect of the seals to the head as well seeing as how there isn't a feature to help locate the seal on the orifices of the head (only the two "pins" on either end of the damper is all that seems to be used for locating it to the head).

I'll post some pictures when I have a chance to get it cleaned up a bit. So if you see similar behavior on your VG, check your dampers!

 

[emhmotorsports]

Just following up. It seems there was a failure in the weld/glue on both the cyan and magenta sides. Was not where I initially thought it was though. I just gently prodded around the seams with a pick to find the "soft" spots where it was no longer connected. Attached photo shows the tip of the pick going into the damper at the bad spot. Being up high on the damper explains how it wasn't making a total mess on top of the heads.

 

[Zoogee World]

Glad you were able to find the problem. Just wanted to make sure you replaced with OEM parts, as if you had used 3rd party, that might explain why they failed so quickly.

 

[emhmotorsports]

Glad you were able to find the problem. Just wanted to make sure you replaced with OEM parts, as if you had used 3rd party, that might explain why they failed so quickly.

Thanks! And thanks for the tip! It's hard to say. This first batch I ordered from Digiprint (they have a lot of stock and ship quickly). The dampers looked to have a real Roland part number, but the cap tops are highly suspect. I'm waiting for my dampers from Roland to show up (it can take a couple of weeks) to compare.

 

[Zoogee World]

DIGIPrint sells both 3rd party and OEM, but the OEM are usually as expensive or more expensive then buying them from a local dealer, so depending what you paid, could probably tell you right away.

 

[Jester]

Thank you for posting the detailed followup to your original message. Very helpful if we ever run into similar problems.

 

[emhmotorsports]

DIGIPrint sells both 3rd party and OEM, but the OEM are usually as expensive or more expensive then buying them from a local dealer, so depending what you paid, could probably tell you right away.

So the dampers from Roland finally showed up today. They came in hard plastic containers, whereas the Digiprint ones just came in a plastic bag. They look virtually identical, but the biggest difference is the wire diameter of the internal spring (Roland ones are larger). Don't know if this is enough to say for sure that the Digiprint ones aren't genuine, but I'll see if these will at least last longer!

 

[JoeJG380]

I'm really digging those Roland dampers. I was using the HHPs that came with my V-Drums for a while, but I'm loving the Remo's that I bought.