Ricoh MP2851 Repeating (10~11mm) white bands in black regions

[rapha]

Hello, need help from anyone familiar with Ricoh copiers - I've attached a photo of the printouts to quickly show the problem. First printout is the page counter report generated by the unit, while the second is a printout from Microsoft Word.

Any leads at all would be greatly appreciated, thanks in advance!

Eric

[mikadonovan]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

That looks like a problem with the charge roller. Maybe time for a new pcu.

[copier tech]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Hello, need help from anyone familiar with Ricoh copiers - I've attached a photo of the printouts to quickly show the problem.

Any leads at all would be greatly appreciated, thanks in advance!

Eric

With that width i'd say an issue with the dev roller.

Take out the PCDU split the PCU & DV unit & inspect.

[rapha]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Thank you mikadonovan and copier tech for the quick reply.

Weird thing is, when I print using SP2902 test patterns, the blacks seem pretty okay (please see new attached photos)

Also, when I plugged the PCU into another MP2851 unit, it also print without any problems whatsoever. Black solid lines and regions all throughout.

[slimslob]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Thank you mikadonovan and copier tech for the quick reply.

Weird thing is, when I print using SP2902 test patterns, the blacks seem pretty okay (please see new attached photos)

Also, when I plugged the PCU into another MP2851 unit, it also print without any problems whatsoever. Black solid lines and regions all throughout.

So are we to assume that the first images are of copies? If so then your problem is in the scanner section.

[rapha]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

So are we to assume that the first images are of copies? If so then your problem is in the scanner section.

No, they're all printouts that don't involve the scanner section.

Thanks for pointing that out, updated my original post to clarify.

[sandmanmac]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

when I plugged the PCU into another MP2851 unit, it also print without any problems whatsoever. Black solid lines and regions all throughout.

So you have a working test machine and the only thing that you've tried is swapping the PCU from the trouble unit into the working machine?
Why not try the other PCU in your problem machine? Why not swap the transfer roller? (My guess is that's the issue)
You have everything available to you to resolve the issue.
Get creative, and let us know the solution

[rapha]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Thank you sandmanmac for the reply.

I only have occasional access to the other unit, so it is only now that I have tried your suggestion.

Indeed, the cause of the problem is the PCU. When I tried the PCU of the good copier unit (putting it on my machine), the blacks were indeed solid.

Now, I'm not sure what to look for inside the PCU (hoping it can be solved by just replacing a minor part and not having to buy one whole new PCU).

I didn't notice anything odd with upper/drum section. But when I took a look at the development/bottom section, the hazy, gradient pattern of the developer/toner on the development roller seems to match the pattern in the printouts. Not sure where the period (approx 10~11mm) comes from though.

Do you think this can be fixed by just replacing the developer powder?

[mga]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Thank you sandmanmac for the reply.

I only have occasional access to the other unit, so it is only now that I have tried your suggestion.

Indeed, the cause of the problem is the PCU. When I tried the PCU of the good copier unit (putting it on my machine), the blacks were indeed solid.

Now, I'm not sure what to look for inside the PCU (hoping it can be solved by just replacing a minor part and not having to buy one whole new PCU).

I didn't notice anything odd with upper/drum section. But when I took a look at the development/bottom section, the hazy, gradient pattern of the developer/toner on the development roller seems to match the pattern in the printouts. Not sure where the period (approx 10~11mm) comes from though.

Do you think this can be fixed by just replacing the developer powder?

Most of the time on this the machine I replace all parts together
Dev, pcu, charge roller, charge roller cleaning roller, dcb and gears

But you can fit a type 1027 pcu unit in this machine just with little modification

[copyaction]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Most of the time on this the machine I replace all parts together
Dev, pcu, charge roller, charge roller cleaning roller, dcb and gears

But you can fit a type 1027 pcu unit in this machine just with little modification

For this model no modification is needed, you just have to manually run developer initialization.

[GIUBOSS]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Thank you sandmanmac for the reply.

I only have occasional access to the other unit, so it is only now that I have tried your suggestion.

Indeed, the cause of the problem is the PCU. When I tried the PCU of the good copier unit (putting it on my machine), the blacks were indeed solid.

Now, I'm not sure what to look for inside the PCU (hoping it can be solved by just replacing a minor part and not having to buy one whole new PCU).

I didn't notice anything odd with upper/drum section. But when I took a look at the development/bottom section, the hazy, gradient pattern of the developer/toner on the development roller seems to match the pattern in the printouts. Not sure where the period (approx 10~11mm) comes from though.

Do you think this can be fixed by just replacing the developer powder?

Have you checked or cleaned the inside of the car? Have you noticed if there is any scattered developer? If it is probable that the drum unit needs to be overhauled by replacing the sponge seals in addition to the materials suggested in the previous posts.
Possibly original consumables

[slimslob]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

Have you checked or cleaned the inside of the car? Have you noticed if there is any scattered developer? If it is probable that the drum unit needs to be overhauled by replacing the sponge seals in addition to the materials suggested in the previous posts.
Possibly original consumables

On a 2851 there is only 1 foam seal, the toner entrance seal. Because of where it is located, it being missing or damaged will caused toner hazing, mostly on the inside of the front door, but not developer loss. Developer loss is caused be prolonged under toning.

[GIUBOSS]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

On a 2851 there is only 1 foam seal, the toner entrance seal. Because of where it is located, it being missing or damaged will caused toner hazing, mostly on the inside of the front door, but not developer loss. Developer loss is caused be prolonged under toning.

there are also long sponge gaskets attached in different places especially in the developer box, at the ends of the magnetic roller, under the magnetic roller and between the top and bottom covers which if old will cause the developer to leak out during mixing.
another tip, if possible replace the paper rising rollers, they are made of sponge and if old they fragment everywhere in the machine and worse to encrust the drum too, I replaced them with plastic ones taken from the old 1027, dsm627

[slimslob]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

there are also long sponge gaskets attached in different places especially in the developer box, at the ends of the magnetic roller, under the magnetic roller and between the top and bottom covers which if old will cause the developer to leak out during mixing.
another tip, if possible replace the paper rising rollers, they are made of sponge and if old they fragment everywhere in the machine and worse to encrust the drum too, I replaced them with plastic ones taken from the old 1027, dsm627

I have never had one of those rubber gaskets between the top and bottom of the development case fail. I have had to replace the 2 gears on the the development roller assembly when they strip. If you have one that is stripping gears frequently, either the passage from the mixing auger to the development auger has gotten partially clogged and causing developer to build up and jam the mixing auger or developer has gotten into the bushings at the back end of the augers. If you check and there is depleted developer in the space around the gears, the bushings are toast. Replace the entire development case.

Also splitting the case would require removing the screws marked with white paint to designate that they are not to be even loosened. Ricoh-USA tech bulletin.

[Juggy]

Re: Ricoh MP2851 Repeating (10~11mm) white bands in black regions

HI

Looks like magnetic Roller in lower development unit.