HL-4570CDW Diagnostic Question

[jccorbi]

Hi .. I have a Brother HL-4570CDW that is printing a heavy cyan line (see attached scanned image) down the left side of the page.
I've cleaned the interior and replaced the Drum unit and the Belt unit and, of course, all the cartridges.
The line is visible on the Belt when I check it after printing (not before).

Any ideas on what to look at next is appreciated!

 

[PeterBJ]

Here you find several manuals for the Brother HL-4570CDW printer, including technical reference manual and service manual.

 

[jccorbi]

Here you find several manuals for the Brother HL-4570CDW printer, including technical reference manual and service manual.

Thanks!

 

[jccorbi]

I've looked through the manuals - to the best of my ability and do not see the issue I described addressed.
I'm really just looking to get pointed in the right direction -ie. where to look for a cause.
For instance, what could cause this - fuser?, only the cartridge? (which is new)., etc.

[Brother HL-4570CDW that is printing a heavy cyan line (see attached scanned image)
See first post for more detail.

 

[thebestcpu]

Hi @jccorbi
That is quite an investment of time and money to pump life back into that printer. Don' forget to consider having a replacement printer.

Yes, you could look at the fuser as well. Note that I am no expert on laser printers, yet I have experience debugging several types of systems. You may not need this reference yet. Here is a link to the step-by-step process of what most laser printers do: https://www.tonergiant.co.uk/blog/2016/12/how-laser-printers-work-ultimate-guide/. Here is the text, and I will note the possible issues that come to mind at each step:

• The moment you press print on your computer, tablet or mobile device, the information is sent to the printer memory, where the data is stored temporarily.
• The printer begins to warm up. This is the point where you usually need to wait, and it’s because the corona wire is heating up and getting ready to pass its positive static charge to the drum.
• As the drum (coated metal cylinder) begins to roll, it received a positive charge across its whole surface. Some printers contain four drums, one for each colour – Cyan, Magenta, Yellow & Black.

If something interferes with that positive charge being placed on the drum, it would cause the streak.

• The laser activates and beams against a series of mirrors to reflect across the surface of the drum(s), imprinting the shape of your print using an opposite negative electrical charge.

If, for some reason, the laser (or other stray light) either directly or through problems with the mirrors/optics, the positive charge could be dissipated and tone wold be placed there

• The toner cartridge and hopper sat next to the drum(s) slowly release positively charged carbon toner particles onto the drum as it turns. The toner is attracted to any areas of negative charge, leaving positively charged areas of the drum untouched.

If there is something in the mechanical movement of these components, it would interfere with any positive charge in the streak area and leave toner.

• The transfer belt rolls the paper through the printer, giving it a positive charge. As it passes the drum, the negatively charged toner is attracted to the page in the shape of your print.

If the transfer belt were dirty with cyan in that area, it would deposit on the paper.

• The toner is then melted to the paper by hot rollers called the fuser unit, and voila, your page is printed.

If the fuser is contaminated, it could create a streak as well.

I hope that gives you some pointers on where to look and why. I know some of these are already covered by the components you replaced, yet I was trying to stimulate your thinking on a path to consider.

John Wheeler