Horizontal black lines on Lexmark T652

**theengel** · 02-09-2015

I'm servicing a Lexmark T652 that had black lines across the page. The pattern indicated it was from the drum. A new cartridge made the problem go away. Two days later, it came back. Another cartridge (OEM) made it go away again. Now it's back. What the heck can be causing this?

**Iowatech** · 02-10-2015

If you got new OEM toner for each of the new drums, please ignore this post. Also feel free to call me rude names for wasting your time if you want (sometimes that's how I learn).
Otherwise, OEM toner may be something to look into. Especially if the user of that machine is making a lot of prints with high toner coverage.
If this happens to be the case, it is probably too late for the two new drums you've already tried, sorry.

**Elmtech** · 02-10-2015

Look at your transfer and charge roll. Especially if they are non oem they can cause these issues. Also worth checking the developer drive assy.

**theengel** · 02-10-2015

I guess I'll start with the charge & transfer roller. They are the only thing that touches the drum. The black line (band, actually) starts at every rotation of the drum. And it does go away when I put a new cartridge in... but it comes back a few days later. I think I'll also do a firmware upgrade.

**theengel** · 02-10-2015

Grrrr... I tried to upgrade firmware today and I keep getting "Programming Error 200." I can't find mention of that anywhere.

This is what the prints are looking like:

Scan3.JPG
But they don't start out this way. We change the cartridge and the print is perfect. Then a few days later, a small black line appears. The line grows wider into a band, and it eventually looks like this.

I think they're opting for a new printer, so I might never know what this is.

**blackcat4866** · 02-11-2015

If I had only seen the image I would have said laser, but changing the drum would not make any difference whatsoever.

The only thing that makes sense to me is drum ground. I once had a Canon iR3570 giving me random black lines crossfeed of varying thickness. I thought for sure it was the laser. I found a refurbished laser on the net, then installed it. The replacement laser was definitely bad, instantly coding out. They never did take it back, by the way.

Next I rebuilt the developing unit. Nope, still doing it. Eventually I took a look inside the rear end of the drum to check the copper drum ground contact. The copper contact was not visible ... and the inside of the drum was blackened. So I popped off the rear drum cap. The copper contact point were burned off. I suspect that it made poor contact from the beginning, eventually burning up the copper contact within 10K. In my case I reformed a LPC (large paper clip), creating my own drum ground, shaped somewhat like a 6 pointed star if you can picture that. It contacted the drum at the outside, and the drum shaft on the inside. Then I glued the drum cap back on. Voila! Fixed drum.

As a test, you should be able measure the resistance from the metal edge of the drum to frame ground. You should get a steady reading close to 0.0 ohms. =^..^=

**theengel** · 02-11-2015

I wonder if they'll let me have the old printer... just so I can find out what the heck this is.

**Iowatech** · 02-12-2015

(The rules from my previous post still apply.)
The picture makes it look a little like the machine has a drum charge failure. That might not explain why the problem went away for a while when you changed drums, but a high voltage board problem could explain the repeating pattern in the lower two bands in the picture.
I wonder if the manual has a timing chart in it. If I have time at work tomorrow, I'll have to check and see if that repeating pattern matches up with anything.