valuejet banding, ever seen this?

[wesley]

Hello everyone,
was wondering if anyone would be kind enough to pass along their wisdom on this problem I am having with my 1204. I think I have tried just about everything I can think of or have heard of.
Have tried these fixes so far but has not worked:
1 cleaned encoder strip
2 messed with PF adjust
3 different heat settings
and other things as well

As you can see in the pics every thing starrts out perfectly, but after traveling about a half inch every thing starts banding.

Any advice on this would be GREATLY appreciated.
thanks

 

[Malkin]

I'm not really an expert in printer diagnosis, but I think that you have some sort of ink starvation issue.

Hopefully others will chime in with more/better info.

 

[wesley]

Thanks Malkin, it seems that way to me too, but why would it lay down plenty of ink for a half inch and then just stop laying down that same amount from there on?

 

[wesley]

A very nice gentleman at Mutoh said it could possibly be dampers need changing. Has anyone experienced this and fixed it with a damper change?
thanks

 

[Stealth Ryder]

A very nice gentleman at Mutoh said it could possibly be dampers need changing. Has anyone experienced this and fixed it with a damper change?
thanks

How old is the printer?

What inks have you used?

Inspect the Dampers, you can usually see if they are clogged which would cause ink starvation...

It could be and most likely is as simple as the Head not Capping correctly...

How old is the Maintenance Assy and is it cleaned and maintained regulary?

 

[wesley]

Thanks Stealth Rider, I have a long time problem with the head capping and have replaced the entire maintenance station. But I still cannot get it to do a cleaning correctly as no ink makes it down to the waste tray during cleaning.
I am using oem inks.
I have tried cleaning all around cap and head with cleaning solution but no help.
Could you possibly explain why it would print perfect for a half inch, then start banding, and how it starts banding at a perfectly straight line after that half inch.
thanks alot

 

[wesley]

oh sorry, It looks as though there is ink in the dampers but how can i tell if there is some clogging going on? The machine is an 08 model
thanks again

 

[Stealth Ryder]

It looks and sounds like the machine is "loosing it's prime", for lack of a better term... Meaning that air could be getting into the vacume of the ink delivery system... This is most commonly caused by the Head not Capping properly...

Remove the Dampes and inspect... The small screen at the bottom inside the damper is what you want to look at...

What inks are you using?

 

[wesley]

Thanks again Stealth Rider, Do you know of any adjustment I can mak on the cap to make it seal around the head better? As I mentioned it is a brand new maint station. I have never replaced the dampers so I will give it a try, the only thing I am unclear about on that procedure is how to get the ink flowing again after the damper change... thanks again

 

[Stealth Ryder]

Press MENU
Press the DOWN button as many times as needed until you see CLEANING
Press the RIGHT button once
Press the DOWN button as many times as needed until you see LITTLE CHARGE
Pres the ENTER button

Do this with the Head in the LOW position

 

[wesley]

Hello eveyone

Well, I did a damper change on 2 dampers and of course now I cant get the ink flowing in those 2 lines... I did a little charge (twice) as Stealth Rider was kind enough to recommend but to no avail. Tried syringing from the tubes going to the waste tray but no help either. (its possible that my tube and syringe system isnt getting a tight draw but it is drawing a little bit of ink through the lines but not drawing anything through the lines of the dampers that I changed)
Would anyone happen to know of something I can do to get the ink flowing through those 2 lines again?
thanks alot

 

[CheapVehicleWrap]

Why did you only replace 2 dampers?

 

[Jeff South Florida]

The best way, is to use the syringe with a y splitter. Put them in the damper part that mounts to the head. Draw ink through the damper. If the damper is good the ink will not flow backwards. The damper will stay primed. When you have all the dampers filled, you need to figure out why the maint. station is not pulling ink.

 

[wesley]

Well I intend on changing all dampers but just wanted to start with 2 to see if my banding problem would get better in that color.
So DSD, are you saying that I need to pull both dampers off of the head carriage and pull ink from both dampers at the same time from the hole that gets the o-ring. If I do this will the ink want to continue to pour out from that hole before I can put the damper back onto the head carriage?
thanks again

 

[artbot]

the fade/starvation... is it universal? put together a file: a square of cyan, magenta, yellow, and black. to see which actual color/s is dropping. also, do a damper swap with failing colors over to print head positions that are not failing. that will tell you if the issue remains at the failing head (cap/head issue) or follows the damper (damper, line, cartridge issue).

other tips:

one thing you can do to see if you are getting a relaxed flow from your supply is observe the polyester membrane on the damper. after you draw ink into the damper, see if the membrane relaxes easily or does it seem to stay under vacuum. if it stays under vacuum (concaved), then you have a clog in your supply. the clog could be near the head or all they way back at the piercing nipple. if it looks suspicious, you need to get a cleaning cartridge and push and pull solution back and forth. pay attention to the amount of force needed to push and pull. if the syringe requires very high vacuum or pressure, that again is a sign of a clog.

when i clean out a line, i use 50/50 butyl cellosolve/acetone (stronger than the usual solution). there's nothing between the syringe and the cartridge that will be harmed by stronger solvent blend. you'll need a standard clear refillable cartridge for the stronger solution. a bad clog, can really hold in a line. so keep in mind that, if clogged, it will require some soaking in the solvent, maybe even a wire sent down the tube from the head carriage.

also, a blocked drain tube can cause these same symptoms. if the damper behaves normally, i'd look there for clogs in the pump, and drain, and just below the caps, or an air leak at any unions or nipples between the caps and the pump inlet. to diagnose you can do a pump tube swap to isolate.

 

[Stealth Ryder]

Find out where air is getting into the system and correct it

 

[wesley]

Yea, I agree Stealth Rider, and thanks to everyone for suggestions. I really feel like the problem is with the cap not sealing good to the head but I have replaced the MS and done alot of other tips and still cant even get ink to flow thru to the waste tray during a cleaning.
Im pullin my hair out over here....

 

[artbot]

so, it's every color dropping out equally? you can diagnose bad cap seals by damper swaps (if some colors work while others don't). or...

to judge if the cap isn't sealing to the head, pull the cap tube off running to the pump and pull some ink, observe if you get bubbles running down the line to the syringe. there will be usually a bit, but not a continuous train of them. if you have a suspicious result cam the capping station/head carriage to it's highest position manually. and redo the pull. no air should be able to seep into the mix with the capping station cammed to maximum height. if you get air at the maximum height, then you probably have a union leaking (tube/cap point) also, when changing pumps, it is possible to have air leaks at the unions. i changed a pump, and soaked a capping station once, only to later find that the union put a tiny split in the cap tube letting air in.

 

[wesley]

Sounds good Artbot, I am going to try that next. But let me ask you this... do you beleive that there is no possibility that the head is not sitting all the way seated inside the cap when attempting a cleaning? Possibly letting air in around the head. If that is a possibility then is there anything that I can adjust to make that seal better?
thanks again

 

[artbot]

first have you isolated it to a single color or a single head? and when you do a cleaning cycle, what do your caps look like? two latent colors as they should be, dry, only one color, overly wet with ink, filled with ink, also pull off the cap top and look under it. is it very wet with ink or just moist?

your ink starvation is showing up so quickly, there should be enough ink in the damper alone to print much more than that. these printer operate on a very delicate syphon. there isn't an actual vacuum inside the ink lines. rather there is positive to neutral fluid pressure linking the the ink to fall toward the head. just raise a cartridge or lower one, and you will immediately see the ink flow leak out the head or quit printing. think if the ink as a chain hanging off of a roof. if enough chain starts to fall down it will drag the rest of the chain to the ground. the ink is that chain very slowly trying to fall out of the print head.

and think if this when a printer prints, it doesn't continuously refresh the heads. it prints and prints and prints. if you draw ink manually into the head from beneath the cap, and you still get instant ink starvation, than you probably have some resistance inside the ink line. i just cleaned out my black line the other day. i was drawing ink into the damper and noticed too much resistance. did the clean, and got much better flow. there are some turns and twists in the ink lines going toward the head, i think there is a tendency to get some gathered sediment/pigment there over the years, slowly building up to a point of resistance.

also, have you made sure that your pump tube/waste lines are clean? take off the union going to the pump and blast cleaning solution down those lines. even if you replaced a pump yesterday. an ink starvation issue can starve the pumps of ink which provide the solvent to keep them from drying out.