VJ1604 banding issue

[bsm]

Hi All,
I have an issue with banding. Done the usual cleaning etc. I had a couple of missing nozzles on the cyan which came back but only have a couple of missing ones on the black which have been gone for a while now and in the past have not made any noticeable difference to the print quality. The banding is obviously much more noticeable when using lower heater temperatures but still there on higher temp profiles. I have also done an alignment print which was ok.
I replaced the maintenance station about 12 months ago and the head is at least 2 years old. I have also attached a pic of some printing we just did on a lower temp paper profile.
Any advice will be greatly appreciated.

 

[heyskull]

If you cannot revive missing nozzles you will be always fighting a loosing battle.
It is amazing how a couple of blocked/failed nozzles can make a low pass print look bad.

If the head is 4 years or older, replace head and head cable.

SC

 

[bsm]

thanks for the info, head is less than 3 years but as I mentioned the 2 black missing nozzles have never been an issue, but it is banding even when there is no black in the print.

 

[heyskull]

Post a test print please?
Also a print of solid Cyan, Magenta, Yellow and Black in low quality and high quality.

SC

 

[bsm]

hey SC, attached low and high quality, bit hard to see from the pics though so attached just the black high quality as well. also attached a pic from the head alignment print, 3A & 3B arent printing at all. cheers Brad.

 

[bsm]

forget the head alignment print, the 3A & 3B are yellow, I reckon that would be why I cant see them.

 

[bsm]

problem may be solved

one of the drain lines from the pump had a bit of sludge clogging it. syringed some cleaning fluid up and down through the pump until it finally got sucked out. Pic attached. will post after some printing with results.

 

[bsm]

not solved

still banding

 

[heyskull]

That's weird.
Whats the Nozzle Check look like?
Maybe an encoder disc or pf adjustment issue.
I have also came across a similair issue latley on a different material. So could also be a material issue.

SC

 

[bsm]

diff material same result, the nozzle print has some of the little dashes on more of an angle than the rest. but this has happened just today.

 

[heyskull]

Could be something as simple as a bit of fluff on the head.
Have a look at the head check for anything amiss.
Also wipe around the outer edge of it with solvent cleaner so it seals well against the cap top then maybe soak it for a while.
I had a deflection on my 1604 this morning but after a quick soak and clean up all was well.

SC

 

[bsm]

did all that to start with. I think it might be a pump problem. no ink draining out when doing a clean. If I put fluid in the top of cap it drains through ok. would explain the banding I guess.

 

[bsm]

solved

Just in case anyone looks at this trying to find an answer to a similar problem.
I turn the machine off at night which has never caused any issues but what I had never done was regularly flush the ink lines through the pump. Sludge had gradually built up in one of the lines and when I managed to clear it it did start to get better. After about 20m of printing and cleaning the line cleared right up and hey presto. Printing great again.

 

[FatCat]

Sorry I didn't see this thread till this morning. Yes, everything you described pointed towards a clogged drain lines. I can't stress enough that with these ValueJet printers keeping the drain lines clean and clear and making sure there is a good seal around the head and cap is the key to a happy and productive machine. Most of the print quality problems I have seen all revolve around this system not working properly. Every week I make sure to run some cleaning solvent down my drain lines in both my machines and of course regular service on the rails, wiper blade and manual head cleanings.

Glad you were able to figure it out, keep it clean and clear and it will make money for you a long time...