[CQ] (MP C4000) Replaced PCU and DEV and STILL have colour issues.

[Richariri]

Ok, I'll just give a brief outline of what I've done so far.

received a used MP C4000 from Ricoh and on testing noticed various copy quality issues; as standard I continued to refurbish the machine and check it all over during the process.

After the refurb I needed to clean the black dev unit due to Void lines appearing on b/w, this cleared that fault and I thought I was all good... how wrong I was

During the colour print test I noticed this same void/faded line appearing in exactly the same place 100% of the time (not the same location as black). I did a checkered test print of all the drums and couldn't see a single issue, cleaned the laser glass etc... I then did a printer test pattern and it appeared straight away, running through the RED (not magenta) pattern. I then did a full dot test pattern which has shown the issue to be with the magenta unit (i think the checkered flag may of been just out of line to show the fading)
I first cleaned the unit with no result, then replaced both the PCU and DEV unit.

I've just turned it back on and the fault hasn't even altered, let a lone cleared. What's happening?

everything points towards it being the magenta unit as I don't get it with any other test patterns although the PDF i'm attaching doesn't show it that well.
It also happens on absolutely ANY colour photo where magenta is used even in the slightest. Doesn't happen if I print a full cyan or yellow page though so it can't be some dust inside the laser unit surely?

guy's and gal's I'm stumped, please help me

[skynetto]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

The first page shows these symptoms
1. Color disaligned
2. Laser dirty (top is OK, bottom is faint)

Hint: have you cleaned the polygon motor and all the lens inside? I mean open the laser assembly to the point where you see the lens (not just the four lens when you remove the laser).

[qbert69]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

Check your Image Transfer Belt. I have seen at least one instance where there was a crease or imperfection in the ITB surface longitudinally and when the colors try to "register" at that location (I noticed that it showed most prominently in your red sample), the dot patterns don't line up to make that particular color and therefore, you have a visual imperfection.

CHEERS!

[Zeldaman]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

Hi there!
Also check the paper-transfer-roller-assy. Sometimes the little discharge-brushes (i know its metal) are bent, giving fine lines and/or noise.
Greetings...

[Richariri]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

Thanks for the quick response

I have inspected the laser unit and it is clean as a whistle. I don't think it's laser as it's definitely not happening on all PCU's

The transfer belt has a what looks like a 'wear' mark straight down the center (two tram tracks in a pale whiteish colour). There's nothing actually on the unit that's wearing it but it looks like this could be the problem.
Any ideas as to what can be causing this as the belt is well within it's life and I don't fancy telling the boss he's got to fork out on one.

EDIT:
checked the transfer roller and it's fine, I've had that before where it snags and causes paper jams.
I've talked it through with level 2 and I'm going to temporarily fit a transfer belt tomorrow to see if this removes the fault or not.

[xuanthu]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

Hi,anyone can help me? I need ricoh MP5000 firmware. My email add : xuanthu986@gmail.com .thanks a lot

[semi]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

I'd remove the laser shutter assembly and see if you still have the problem

[Richariri]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

I'd remove the laser shutter assembly and see if you still have the problem

what do you mean by 'shutter' assembly?

[Gift]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

Laser shutter - this was an issue with the first MPC series. MPC4000 doesn't have a shutter.

[Richariri]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

Ok, fault is cleared now.

*facepalm* it was the laser unit.

had tiny two dots on the glass, they seemed to be stuck to the glass so didn't come off when I cleaned it.. plus you could only see them in the right light.

Thanks for the help guys.

(one more thing, how do I clear this thread as completed???)

[Iowatech]

Re: (MP C4000) Replaced PCU and DEV and STILL have colour issues.

Weird how some things only show up in certain colors. Had a machine where dust in the optics would cause something like that, but only on full color copies and scans.
I think your last post did a pretty good job telling people that the thread is completed. If you are looking for a way to turn it completely off, that procedure has been gone for some time now as far as I have seen.