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

[GIUBOSS]

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

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.

Sometimes I also replace the other 3 lower gears in addition to the two you described, they are the same as the mp2000, instead for the sponge seals I ordered them as Ricoh spare parts such as AA15-3442 and adapted, these drum units are more expensive than Type 1027 PCUs

[ShonRipz]

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

Problem with development. a bad charge would cause Dark lines, not white voids. check if your transfer roller has a line or groove in it. Next i would check amount of developer in unit, could be low.

[slimslob]

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

Sometimes I also replace the other 3 lower gears in addition to the two you described, they are the same as the mp2000, instead for the sponge seals I ordered them as Ricoh spare parts such as AA15-3442 and adapted, these drum units are more expensive than Type 1027 PCUs

I have had to replace the development case a couple of times when the plastic post that the idler gear mounts on has broken off.

[slimslob]

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

Problem with development. a bad charge would cause Dark lines, not white voids. check if your transfer roller has a line or groove in it. Next i would check amount of developer in unit, could be low.

But if it has ran under toned for a while, developer will start being pulled to the drum which will cause the problem he has.

[CopyBats]

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

When was the last time PCU/PCDU was changed on this machine? Looking at the counter ( if it is original) at 52K copies and considering how old this machine is, you would be better off servicing the entire unit or replacing the entire PCDU.

[Oze]

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?

As soon as I read "hoping it can be solved by just replacing a minor part and not having to buy one whole new PCU"...I stopped reading.
Save yourself a headache and DON'T save a dollar for the customer.
Replace the pcdu and walk away.

[Phil B.]

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

But if it has ran under toned for a while, developer will start being pulled to the drum which will cause the problem he has.

+2 this was a common prob on the original 1027 unit. People would iggy the message and have other techs negate the warning and also Stop Printing message.

they will start dumping and prints/copies will get 'gritty'.

[rapha]

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

I did split and inspect the upper (drum) and lower (developer) sections of the PCU. There doesn't seem to be any spillage in developer powder. Just a bit messy with toner powder.

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

How does one check for spilt developer? When they spill out of the development unit, are they just contained within the PCU or do I have to check outside of the PCU as well?

The paper rising rollers actually did decay with the sponge crumbling and fragmenting everywhere. Problem was ignored and the copier was still used until the printouts became unbearably dirty with solid raised patches (presumably sponge crumbs fused onto the paper). At that point, upon inspection, indeed the sponge has encrusted permanently onto the drum too and can't even be removed with alcohol. The paper rising rollers have now been removed totally and the copier is running without them. Also, the drum and cleaning blade were replaced with new ones recently.

Is it possible that sponge crumbs got into the development unit as well and ruining the developer powder? Which explains the faint white patches in the black regions?

[rapha]

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.

The junction between the toner dispensing unit and toner supply entrance on the PCU side did seem compromised and very messy upon inspection. Do you mean that this condition could have caused undertoning and therefore developer loss, causing the faint white banding (in black areas) in the printouts I attached?

But if it has ran under toned for a while, developer will start being pulled to the drum which will cause the problem he has.

Assuming this is what really happened, where does the developer that got pulled to the drum eventually go? How can I tell that the developer has been depleted, since I don't know what the normal/nominal amount for this unit should be?

[rapha]

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

When was the last time PCU/PCDU was changed on this machine? Looking at the counter ( if it is original) at 52K copies and considering how old this machine is, you would be better off servicing the entire unit or replacing the entire PCDU.

This is actually a surplus machine, the shop from which it was purchased had the habit of reassembling and swapping good parts around. So, the real age of the PCU is unknown, unfortunately. The drum and cleaning blade were replaced with new ones recently though.

[rapha]

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

+2 this was a common prob on the original 1027 unit. People would iggy the message and have other techs negate the warning and also Stop Printing message.

they will start dumping and prints/copies will get 'gritty'.

Now that I know it's the PCU that's causing the problem, I will next try using just the lower (development) section of the the good PCU. If the problem goes away, then the problem is with the developer/development unit.

[rapha]

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

As soon as I read "hoping it can be solved by just replacing a minor part and not having to buy one whole new PCU"...I stopped reading.
Save yourself a headache and DON'T save a dollar for the customer.
Replace the pcdu and walk away.

The copier is just a refurbished/surplus one that was purchased for around USD650 four years ago. It ran perfectly fine that time, but from then until now, only 1,500 pages were printed (or 375pages/year). So one would be hesitant to spend USD500 for a new PCU.

[sandmanmac]

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

The copier is just a refurbished/surplus one that was purchased for around USD650 four years ago. It ran perfectly fine that time, but from then until now, only 1,500 pages were printed (or 375pages/year). So one would be hesitant to spend USD500 for a new PCU.

First of all, it's not $500 for the type 1027 PCU that has been suggested multiple times and works perfectly.
or secondly, then buy the OEM parts, and rebuild it PROPERLY for about $150

Check please...I'm done with this thread

[GIUBOSS]

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

I did split and inspect the upper (drum) and lower (developer) sections of the PCU. There doesn't seem to be any spillage in developer powder. Just a bit messy with toner powder.



How does one check for spilt developer? When they spill out of the development unit, are they just contained within the PCU or do I have to check outside of the PCU as well?

The paper rising rollers actually did decay with the sponge crumbling and fragmenting everywhere. Problem was ignored and the copier was still used until the printouts became unbearably dirty with solid raised patches (presumably sponge crumbs fused onto the paper). At that point, upon inspection, indeed the sponge has encrusted permanently onto the drum too and can't even be removed with alcohol. The paper rising rollers have now been removed totally and the copier is running without them. Also, the drum and cleaning blade were replaced with new ones recently.

Is it possible that sponge crumbs got into the development unit as well and ruining the developer powder? Which explains the faint white patches in the black regions?

All the developer is found only in the pcu box and precisely under the magnetic roller, with the pcu outside the copier I guess you will have cleaned the inside and seen if the developer is around under the pcu group housing, so you have left to replace only this in whole or the individual parts consumed; I would replace the paper riser rollers, sooner or later they will create problems for you, better be careful. Very insidious and hard to remove the crumbled sponge for the pcu

[Oze]

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

The copier is just a refurbished/surplus one that was purchased for around USD650 four years ago. It ran perfectly fine that time, but from then until now, only 1,500 pages were printed (or 375pages/year). So one would be hesitant to spend USD500 for a new PCU.

And even so...how many times do you think you can just keep refurbishing the original pcdu?
At SOME stage they ALL have to be replaced....I think it's your time
I think I'm done with thread as well Sandy...you can lead a horse to water etc