MP C4000 faint black toward operator side of page

[freginold]

Has anyone seen this issue? On a MP C4000, when you copy or print in black, the op side of the page (toward the front of the machine) is faint, but the non-op side is nice and dark. Replaced PCU, DV unit, cleaned ID sensors, checked ITB unit.

The weird thing is, when you reset the K pcu using sp3902, the problem goes away for a copy or two, then comes back. Has anyone seen this? Motors seem okay.

[slimslob]

Re: MP C4000 faint black toward operator side of page

Shutter plate is sticking.

[freginold]

Re: MP C4000 faint black toward operator side of page

Shutter plate is sticking.

Thanks, I'll check that, but not sure why the shutter wouldn't stick when you reset the drum counter.

[slimslob]

Re: MP C4000 faint black toward operator side of page

Thanks, I'll check that, but not sure why the shutter wouldn't stick when you reset the drum counter.

Common problem. A lot of techs remove the entire shutter from the laser unit the first time this occurs.

[turbojetboy]

Re: MP C4000 faint black toward operator side of page

No shutter on Mpc4000. Check small black plastic ptr holder that is screwed to machine main frame just under fuser for cracks or broken pieces. There is a front and rear one, and I have seen the front one crack and cause a light area about an inch wide on the front side of image.

[freginold]

Re: MP C4000 faint black toward operator side of page

No shutter on Mpc4000. Check small black plastic ptr holder that is screwed to machine main frame just under fuser for cracks or broken pieces. There is a front and rear one, and I have seen the front one crack and cause a light area about an inch wide on the front side of image.

thanks, we'll check that too, but it's about half the image (op side) that is faint, and it only happens with black, colors come through fine.

[Zaxxon]

Re: MP C4000 faint black toward operator side of page

Chek the PTR unit hinge lower back side, these tend to break.
You can get this as a unit or sparepart (different part number as you need additional parts).

The parts turbojetboy described often breaks when the PTR unit hinge fail or vise versa...

[imihm]

Re: MP C4000 faint black toward operator side of page

No shutter on Mpc4000. Check small black plastic ptr holder that is screwed to machine main frame just under fuser for cracks or broken pieces. There is a front and rear one, and I have seen the front one crack and cause a light area about an inch wide on the front side of image.

Hi there

Clean the polygon motor sides.

Thanks

[freginold]

Re: MP C4000 faint black toward operator side of page

Chek the PTR unit hinge lower back side, these tend to break.
You can get this as a unit or sparepart (different part number as you need additional parts).

The parts turbojetboy described often breaks when the PTR unit hinge fail or vise versa...

Thanks, that hinge is good.

[Bantams]

Re: MP C4000 faint black toward operator side of page

Black Dev Drive Clutch..............

[freginold]

Re: MP C4000 faint black toward operator side of page

Black Dev Drive Clutch..............

That's my guess too, waiting to see if someone can check that when they are over there.

[andy227]

Re: MP C4000 faint black toward operator side of page

Old thread, but, freginold did you ever solve this and what was it ??????????

[freginold]

Re: MP C4000 faint black toward operator side of page

I actually got transferred to another territory, but it was solved eventually I believe. if I can find out who did what I'll let you know. are you having the same issue?

[andy227]

Re: MP C4000 faint black toward operator side of page

freginold, thanks for getting back. Yes I was having exactly the same issue, and while researching it I came across your old thread and wanted to know how it concluded. My suspicions fell on the laser shutters also and I started another thread trying to understand how the shutter SP adjustments worked, with no positive feedback yet. I figured it out though. On SP 2-914-001 'open', range 1 -50 with default 38, if the setting is on '1' the copy is barely viisble, on '50' it is nice deep black. My first action was to remove and open the laser unit incase the optics were dusted over , but that made no difference, and next I was going to remove the shutter as per many advises from others. When I checked 2-914-001 it was set to a value of '9' !!!! and 2-914-002 was set to value of '2' !!! instead of the default 38. When I put the value back to 38, hey presto, a beautiful copy restored. Dunno how the values got to that silly low level, my colleagues said it wasn't them, maybe a voltage spike ? Who knows. At least problem solved and we learned something in the process. Before yanking out the shutter unit , check 2-914-001 is at default 38, or bump it up to 50. If that doesn't work, go to plan B and maybe yank i out like others have said. Take care.

[freginold]

Re: MP C4000 faint black toward operator side of page

That's great to know. I'll definitely keep that in mind for future issues. Thanks for passing along the info, and glad you got it fixed!