Printing Consistant Lighter Bands

[jessign78]

We recently replaced the valve assembly, maintenence assembly, and main board on our 1604 Mutoh Valuejet.

It was printing lighter bands most noticably in solid darker colors that led us to purchase the new main assembly around two months ago.

That seemed to do the trick to fix the problem, but now after replacing the main board it is prining lighter 1" bands about every 3" consistantly, evenly spaced apart.

Any ideas on how to fix this? We did have to update the firm ware after installing the main board.

Thanks!

 

[J Hill Designs]

hard (nigh impossible) to see anything in the picture you posted

have you cleaned your encoder strip(s)

 

[Malkin]

I had a print issue last week that looked just the same. Turned out it was because I decided to remove all the pinch rollers except the outer 2 AND loaded a full 54" x 50yd roll of vinyl. The 2 rollers were not enough pulling strength on the full roll.

 

[jessign78]

Yes, the encoder strips are clean. Just seems odd that this started happening right after the new main board was put in. All the print rollers are on the machine and seem to be working fine. The PF is right on the mark too.

 

[genericname]

Wish I had a solution, but I might at least be able to offer a temporary workaround.

Our Mimaki JV3 does this as well, but only on 4, 8, and 16 pass modes. 6 pass works fine.

 

[jessign78]

I think it has something to do with the dry heater and the rate at which it rolls up on the bottom. There is a bump that the manufacturer made in the plate that the vinyl rolls off of after it is printed on. It is pulled tight on that dry heater when the arm is in the lowest postion before the motor rolls it up further. I think it is just enough heat from staying in that position long enough that it changes the color slightly.

I will lower the heat on the dry heater or not use the bar to automatically roll it up on the bottom. Certain colors of the CMYK must be affected by the heat more than others because this banding is not that visible on some solid colors I print.

Thanks to those who tried to help.

 

[Impresa]

You should clean the paper feed encoder. Its on the left side of your printer. Its a round plastic That moves the paper forward. And clean with a Small brush the sensor too.

 

[quality]

I had same problem and i solve it with bi-direction adjustment, waves not match and after few pases print is lighter