Registration Problem

[33CRP]

I have a Konica Minolta BizHub C450 that has developed a color registration problem. Most noticeable on color type. The first sheet printed is in register. The next sheets are not but it's 1/2 the sheet. As in running 8.5" x 11 2up, the first 8.5" x 11 is out of register and the second 8.5" x 11 is in. I've replaced everything, IU's, transfer belt & transfer roller but still have problem. Went into service mode and did the registration adjust. I've cleaned all the heads (LPH's etc) with alcohol but nothing is helping. Has anyone seen this problem before or knows what's causing it?
Thanks

[fixthecopier]

I would think the reg clutch is slipping. Change it.

[33CRP]

Are you talking about the clutch on the paper transport section where the transfer roller is attached?
Thanks

[fixthecopier]

That's the one.

[33CRP]

OK Thanks, I give that a try.

[33CRP]

Replaced the paper transport clutch but that didn't fix the problem. Still out of register.
Could it be the loop sensor that's located before the fuser?

[Synaux]

Replaced the paper transport clutch but that didn't fix the problem. Still out of register.
Could it be the loop sensor that's located before the fuser?

I would at least inspect the loop sensor if not try replacing it and also clean the IDC sensors below the tranf belt.

Also, does this happen with internal test prints too?

[allan]

Mmm P-21 could be dirty idc sensors. Color registration not image registration.

[33CRP]

Thanks for the reply's.

Here is a more accurate description of whats happening. The very first 11 x 17 that come out of the press is in register but then the next sheets that continuously feed, the first half of the page is out of register and the second half is good. This happens when feeding out of both the tray or bypass. (The bypass on the MGI, see below, is actually a press feed that continuously feeds one sheet at a time.) It appear to be the magenta that moves. If the press hesitates between sheets fed, for example to stabilize or a feed issue, when it restarts printing the first sheet is in register again and the rest are not good as stated above.Also when running 8.5" x 11" out of the large capacity tray, which comes out landscape, they all seem to print fine.

My problem is that I can't find anyone willing work on this machine. This Konica Minolta Bizhub C450 is the print engine on my MGI DP40 digital press. Because MGI is on their 5 generation (they'd love to sell me their new XL8700 at $400,000) they no longer have people to work on this machine. I've contacted KM and independents but no takers. So I have been doing all the repairs myself. Even pulling out the LPH chassis to replace the black LPH.

Any help would be GREATLY appreciated!
Thanks
Gary

[fixthecopier]

Although this is not your issue, I noticed you said it was doing it on 11x17. I had a 550 that would wrinkle only 11x17. It was a paper dust build up on the reg roller. It was causing it to slip a little in the center of the page as it tried to grab it. The reg roller can be cleaned with alcohol.