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Xj-740

jaly723

New Member
How often do the pumps need replaced. There are 3 of them on this printer. I print a lot of solid colors and about 5' into a print it is starving for ink on the print. I have changed just about everything on this printer. I was wondering if the pumps could cause this problem THanks
 

jaly723

New Member
Xj740

The problem started about 6 months ago. I have replaced all new heads, capping station, dampers, cables, etc. I am getting good ink on a test print as all the heads are firing good. I did change the grip rollers around 6 months ago so that could be a factor also. I dont think this could be the problem, but not sure. Ive tried everything. Even had a Roland technician come out several times and he couldn't fix it.
 

CS-SignSupply

New Member
Any specific color(s) starving? The pumps are considered to be lifetime pumps and more than likely not the issue.

Seems like one group or an individual head would starve rather than all ABC Groups together.

Could be air in the line from anywhere.

What ink/cartridge system being used?
 

Jack Knight1979

New Member
I have a 745. I feel your pain.

Bulk or aftermarket inks can be a huge problem.
If you're running OEM inks I suggest getting a set of the large screen dampers off ebay. these have taken care of my problems for the most part.

The pumps and motors don't affect drop out banding from starvation usually.

Please don't buy new pump motors. You don't need them.

A couple things you can look at would be the large screen dampers, OEM ink, a dying head.

Another common problem that causes this is overall ink limit in the profile. Have you tried a different profile? Roland says anything around 170% causes problem. I'd say anything 190% can cause starvation on certain material.

Another issue is bi-dir calibration. Your head could just be off. To do a good calibration you need to be in service mode. Another fault is slack in the carriage drive unit. (cable or belt)

I realize that this is a starvation banding as it happens into the print, but these are the the faults on the printer that you need to stay on top of for good printing.

The last two things I can think of would be humidity. You'll need a humid space to prevent banding. Lastly you could have a clog in the cart needle. Not likely, but possible.

Are you getting a nice pull of ink from a syringe hooked up to the damper?

Best of luck to you. Don't get discouraged. If you spend some time on it, you'll get it sorted out.

If you're not on OEM flush the system and try a set and see if that helps your problem.
 

cdiesel

New Member
Like Jack said, you don't need pumps. Although the name sounds like they're pumping ink for printing, they're not.

After you're seeing the "ink starvation", stop the printer, bring the heads over to the service side, and look at the face of the heads. Are you seeing ink accumulation?

We had a very similar problem and could not for the life of us figure out what it was. After replacing a few parts, we realized it was not a mechanical failure at all, but static causing accumulation on the heads themselves. We added moisture to the air and the problem has been gone ever since. XJ-740 here too.
 

Jack Knight1979

New Member
Nice!

Like Jack said, you don't need pumps. Although the name sounds like they're pumping ink for printing, they're not.

After you're seeing the "ink starvation", stop the printer, bring the heads over to the service side, and look at the face of the heads. Are you seeing ink accumulation?

We had a very similar problem and could not for the life of us figure out what it was. After replacing a few parts, we realized it was not a mechanical failure at all, but static causing accumulation on the heads themselves. We added moisture to the air and the problem has been gone ever since. XJ-740 here too.
 

CS-SignSupply-TT

New Member
The more questions you ask, the more answers you receive. Therefore, you learn the ins and outs of OWNING and OPERATING a wide format digital printer. Yes, you will get your hands dirty. But your investment in time and effort will come back to you over and over and over again. Your 740 is a beast and it should be a beast in profit to you.
 

jaly723

New Member
xj740

thanks for all the replies. I will try some of the things mentioned above. I swear its not static as the humidity in the room is about 40%. I have had this printer for about 5 years and it has just started doing this problem. All the heads are replaced (about 6 months ago). There possibly could be air in one of the lines, so I'll go over all them again to make sure. I have done everything under the sun, even got a Roland tech out several times and he can't fix it either. I can print a photograph picture just fine, but when I print a solid color then about 5' into the print it will start starving and fading out in the ink. I have printed solid colors on this in the past for several years with no problem.
 

cdiesel

New Member
You've got to narrow it down. Print until you see the problem again. Immediately stop, do a test print, and visually inspect the heads by moving them over to the service side. Post the pics.

Actually seeing what is going on will help us diagnose the problem.
 
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