Roland BN-20 help - intermittent printing

[ITK2023]

Hi, hopefully someone can offer some ideas about the cause of the problem. My diagnostic skills are used up!

I have had this BN-20 from new since 2019, used pretty much every day and everything was fine until just before Christmas when it decided at the start of a new print to print almost nothing. A few cleans and leaving it over the Christmas break and it was back to working fine. Unfortunately it is a pattern that has kept repeating itself since.

It has had new wipers and a cap top (the cap top solved the problem after replacing for a week before it gave up again). It prints with no problems for about a week, and then either when starting a new print, or printing the second set of crop marks after a print it will start printing as if 90% of the nozzles are blocked. Running cleans and cleaning manually including head soaks slowly brings it back, but eventually it will decide not to print properly again after about a week.

Any tips or ideas are welcome!

 

[Zoogee World]

When it does this, is there ink in the lines?

 

[netsol]

that is a DX7 head
i wonder if it has those weird little filters like my mutoh has (one on each ink line)

 

[cornholio]

Are you using original ink/parts?
Sounds like the captop isn't making a good seal.

 

[ITK2023]

I've always used Roland inks and parts, all the parts are clean - so there shouldn't be anything preventing a good seal. can the cap tops be adjusted?

There is always ink in the lines. I did take them off thinking there must be a blockage, but no sign of anything unusual. It is never just one colour either, all 4 will drop out at the same time.

 

[cornholio]

Officially, you shouldn't need to adjust the capping position. There is a jig/tool to mount the cap mechanism correctly, but I have never used or seen it.
It could also be the plastic part right of the cap, where it gets pushed by the head bracket.

I would definitely check the capping function/seal with a syringe. If you close one tube and suck on the other, you shouldn't see bubbles/foam in the syringe.

 

[ITK2023]

Officially, you shouldn't need to adjust the capping position. There is a jig/tool to mount the cap mechanism correctly, but I have never used or seen it.
It could also be the plastic part right of the cap, where it gets pushed by the head bracket.

I would definitely check the capping function/seal with a syringe. If you close one tube and suck on the other, you shouldn't see bubbles/foam in the syringe.

I have done the "syringe test", I would say it was 90% ink with a few bubbles visible at the top.

 

[Zoogee World]

Now that you've pulled ink through, are you getting any better results?

 

[ITK2023]

Somewhat better after a clean or two, but let's see how long it lasts for!

 

[ITK2023]

So far using the syringe has got everything working as it should - though I'm not sure exactly what it has done to solve the problem or if it has just highlighted that something else needs replacing. Any ideas?

 

[Zoogee World]

Sounds like it may be one of the following, either the dampers need replacing, there is a leak in the ink lines or the cap top isn't sealing correctly.

 

[ITK2023]

I didn't notice any leaks in the ink lines when I had all the covers off to replace the cap top.

Dampers may well need replacing, but would they block for all colours at the same time?

Cap top not sealing is probably the most likely of the problems, what can be done to improve the seal? The current one is only a few weeks old and a genuine Roland part.

 

[Zoogee World]

For the cap top, are you certain that it was installed correctly? It's pretty easy to tell if the cap top is the issue, when you try to pull with a syringe if you're getting a bunch of air and a bit of ink when pulling or you hear an air leak sound.