Lines on MP 501

[mikadonovan]

Hey All. Hope everyone is well. I have a bunch of MP 501's that are getting horizontal lines on solid areas. It kinda looks like a charge roller issue, but alas it is not. PCU, charge roller have been replaced, and the issue remains. Am I looking at a dev unit issue? I am not very familiar with this model. Thanks, Mika

[luca72]

Re: Lines on MP 501

Hey All. Hope everyone is well. I have a bunch of MP 501's that are getting horizontal lines on solid areas. It kinda looks like a charge roller issue, but alas it is not. PCU, charge roller have been replaced, and the issue remains. Am I looking at a dev unit issue? I am not very familiar with this model. Thanks, Mika

hi Mika, the white lines you mean, are the big, clear ones? or the small ones that can be glimpsed in the black?

[mikadonovan]

Re: Lines on MP 501

This might be a better pic (jpg). Image is an 11% black, so it should be solid light gray. They are white lines about 5 mils apart across the entire image. This image prints ok to other machines.

[luca72]

Re: Lines on MP 501

This might be a better pic (jpg). Image is an 11% black, so it should be solid light gray. They are white lines about 5 mils apart across the entire image. This image prints ok to other machines.

it seems a problem of the development unit, try to turn it a little forward, and a little back several times...and if metal, try to rub well throughout the surface, the magnetic roller with piece of paper to dry your hands, (the one a little rough), rotating it in the direction where it remains without toner attached.... check also the metal conctact.
I must say that it will be my monitor, or I am blind, or because I am colorblind, but I do not see the lines!...I trust the description...LOL

[slimslob]

Re: Lines on MP 501

This might be a better pic (jpg). Image is an 11% black, so it should be solid light gray. They are white lines about 5 mils apart across the entire image. This image prints ok to other machines.

Are the lines parallel to or perpendicular to the direction of paper feed. Personally I do not like full bleed test prints as they are susceptible to some many fill problems. What I prefer if the Checker Flag test pattern.

[mikadonovan]

Re: Lines on MP 501

Ok, on this jpg of a test print, look at the grey area at the top underneath the black area. It is a pretty good representation of the issue occurring over all of it. The vertical white lines are part of the test pattern. The issue is the horizontal lines (perpendicular to paper feed). PS, I really don't like these machines. Yea! you can actually see them on this one.

[luca72]

Re: Lines on MP 501

Ok, on this jpg of a test print, look at the grey area at the top underneath the black area. It is a pretty good representation of the issue occurring over all of it. The vertical white lines are part of the test pattern. The issue is the horizontal lines (perpendicular to paper feed). PS, I really don't like these machines. Yea! you can actually see them on this one.

Seem a defect of hvt board, or ipu, or also laser
can generate a similar defect
You reamain ti take another mp501, and change part since to isolate the problem

[mikadonovan]

Re: Lines on MP 501

it seems a problem of the development unit, try to turn it a little forward, and a little back several times...and if metal, try to rub well throughout the surface, the magnetic roller with piece of paper to dry your hands, (the one a little rough), rotating it in the direction where it remains without toner attached.... check also the metal conctact.
I must say that it will be my monitor, or I am blind, or because I am colorblind, but I do not see the lines!...I trust the description...LOL

I gave the mag roller a good scrub with a piece of paper, no joy. Development units are on order.

[luca72]

Re: Lines on MP 501

Ok, on this jpg of a test print, look at the grey area at the top underneath the black area. It is a pretty good representation of the issue occurring over all of it. The vertical white lines are part of the test pattern. The issue is the horizontal lines (perpendicular to paper feed). PS, I really don't like these machines. Yea! you can actually see them on this one.

Seem a defect of hvt board, or ipu, or also laser
can generate a similar defect
You reamain ti take another mp501, and change part until to isolate the problem

[luca72]

Re: Lines on MP 501

I gave the mag roller a good scrub with a piece of paper, no joy. Development units are on order.

let me know, when fixed... I was intrigued by this defect.

[slimslob]

Re: Lines on MP 501

Ok, on this jpg of a test print, look at the grey area at the top underneath the black area. It is a pretty good representation of the issue occurring over all of it. The vertical white lines are part of the test pattern. The issue is the horizontal lines (perpendicular to paper feed). PS, I really don't like these machines. Yea! you can actually see them on this one.

THe impression I get is a lot of small toner clots in the development unit that are momentarily blocking the doctor blade and then clearing out only to work themselves back around. I have seen that happen when the machine gets too cold over night and condensation occurs in the PCDU. If anti-condensation heaters are available, install them before replacing the developer to prevent future problems.

[mikadonovan]

Re: Lines on MP 501

THe impression I get is a lot of small toner clots in the development unit that are momentarily blocking the doctor blade and then clearing out only to work themselves back around. I have seen that happen when the machine gets too cold over night and condensation occurs in the PCDU. If anti-condensation heaters are available, install them before replacing the developer to prevent future problems.

These are all off lease units, probably stored in a cold warehouse, and then transported in an unheated box truck from Dallas.