DocuColor 250 family - White powder on drum PCR rollers

[Caffeine]

Hello!

I'm wondering if this is a known issue, or "just the way it is"... Though it is subjective, it seems to me that the PCR rollers in my CMY drums become coated in a white powder MUCH more quickly than they used to. To the point that I have some drums get so coated in the powder that print quality is severely diminished even after only about 10% use. Back in the "olden days" of the purple drums from Japan, I could frequently run my drums all the way down to 0%, and then continue running them (despite the requests to replace!) for many, many thousands more prints.

These days, with the green drums, I never get to 0%. I often don't even get close. Though the drum itself is fine, it is the PCR that has gone bad.

I've noticed that the cowl that holds the PCR used to have a white spongy strip in there to rub the roller and presumably keep it clean. More recent drums have a gray brush-like strip. Don't know if they're related.

Is there anything else in the machine that might be the source of the white power? The age of my 2nd BTR or Transfer Belt assembly, perhaps? (They are ancient... But I clean them now and then and since print quality isn't diminished, I've continued using the same ones.)

I noticed that old developer material and old developer housings cause a lot of toner "dust" to kick up. But that is the color of the toner, not white. Also, I am using only authentic toner. No generics.

Two machines exhibit the same problem. I've replaced all four developer housings with brand new ones in both, and of course replaced the developer material at the same time. One machine has 3.1mil and the other 2.6mil prints. So they're not young! 2nd BTR's and transfer belts/assemblies are original in both machines. (!!) Belt cleaners are replaced as needed, but I do sometimes push my time on them a bit. Suction filters are often cleaned and replaced.

Does anyone have any advice? Is the white powder just some additive in the toner? Or could my ancient 2nd BTR be involved? (I have this extremely vague memory of a SearchLite tip about white powder from the 2nd BTR contaminating drums, but can't find it any more and can't for the life of me figure out how material from the BTR could get all the way from there to the PCR's of the drums without getting caught by any of the many cleaning blades between those two components.)

I've attached a picture of a particularly bad one from the yellow position. As you can imagine, this drum is useless anymore. Print quality is SHOT. I've tried cleaning the PCR roller (very carefully) with alcohol, and they come clean nicely, but are often damaged by the buildup and although marginally improved, still pretty much useless after cleaning.

Thanks, and sorry for the long post... I've tried, I just can't do "short"!

Bad PCR.jpg

[davidj7]

I do clean the PCR's in my machine . We use a locally available cream for that . I dont think you will get that anywhere. What you can do is change the PCR's when you see the white powder coating .

Contact www.magnetone.com.sg They make replacement rollers.

[bojans]

We all have the same problem. I always thought that white thing came from toner.
Do not clean charge roller with alcohol. Just use cloth. It's a little better, but never can be the same as new.
I'm in touch with one guy ho has charge rollers from China, and claims that it work. Price is around 10€ but i never tried. Next time I visit his country will take couple rollers and give a try. Have a bunch of good drums and don't want to throw it. Do you any have experience with those rollers?
Cheers

[kalindd]

Check the cleaning mechanism. It is shared with black corotron cleaner. There is a small part that is breaking inside the the whole assy, and the BCR cleaner will not work at all. That how you drum needs to be replaced very soon.
see here DC252 Premature Drum failures

[Caffeine]

Check the cleaning mechanism. It is shared with black corotron cleaner. There is a small part that is breaking inside the the whole assy, and the BCR cleaner will not work at all. That how you drum needs to be replaced very soon.
see here DC252 Premature Drum failures

This is promising... I never realized that the corotron cleaner motor also had any kind of involvement with the color drums as well. I thought it was solely for driving the corotron cleaning brush forward and backward.

So I went into component control (dC330). The only relevant codes I could find were 091-009 (BCR Scorotron cleaner mot_1400PPS (CW) hi current) and 091-010 (BCR Scorotron cleaner mot_1400PPS (CCW) hi current).

I ran 091-009 a couple times, and sure enough, the corotron cleaner brush started working its way out. So I opened the drum drawer and ran it again with a flashlight on those metal fingers which apparently push the cowl of the BCR, which hold the cleaning brush, down onto the BCR surface. They didn't move. I could clearly hear the cleaner motor working, though, even with the drawer open.

Opening up the machine to get to the back area where the cleaning motors and its cam gears and all are will have to wait until I'm not slammed with printing jobs, but unless there is some mechanism that prevents the metal fingers from operating when the drawer is open, it looks like mine aren't working.

I'll definitely report back on what I find, and thanks for the tip!

[Caffeine]

Brief followup... I checked the other machine I have, and the metal fingers on it DO pivot down to push the BCR brush onto the BCR even when the door and drawer are opened using dC330 and run code 091-009 / 091-010.

So this confirms something is wrong with one of my machines. And it is true that its drums did fail decidedly earlier than the other machine. Though I was kind of hoping this would fix both! haha But it looks like this particular problem isn't evident on one of the two.

[Milo Wilson]

Take the charge roller off the drum, hold under running water and use your hands to rub the film off. Works great and improves the quality, I do it all the time.

[Caffeine]

Take the charge roller off the drum, hold under running water and use your hands to rub the film off. Works great and improves the quality, I do it all the time.

Hey, thanks. Yeah, I've done that, Windex, alcohol, etc... Tried lots of different ways of cleaning them. I've not really noticed a big difference in the end result with any of the methods. I settled on alcohol because it is so quick and easy and can do it right in office without needing to go to a sink. And dries quick.

The problem I bump into with cleaning them is that invariably I don't do it soon enough, and it builds up to the point where it has actually scoured a mark into the roller.

Do you have any thoughts on the 2nd BTR roller? I've always just kept using them until I see print defects, which is never really. So I'm still using my original 2nd BTR assembly on all my machines, and one is up to 3.3mil prints! The "supposed" interval is 300k, so I'm three million prints over the interval! haha But with fresh drums, print quality is absolutely pristine, so I've just kept using it. I have cleaned it out, since it had filled up with waste toner in the reservoir, but do you know of any reason NOT to continue using a 2nd BTR that old? Other issue it may be contributing to?

Same with the transfer belt and entire transfer assembly. They're original, but still print nicely. I have had to replace the little silver home position patch on one machine, though. It had peeled off.

[Caffeine]

Have a bunch of good drums and don't want to throw it. Do you any have experience with those rollers?

I've had mixed success with generic BCR/PCR rollers... I had some from one vendor that worked just fine. Put them in and viola, everything is honky dory provided your OPC is still good. Then I got some from another vendor, and they looked absolutely identical in the way they were packaged such that I thought that maybe they were sourced from the same place, but the second batch were complete failures. They didn't even slightly work. Prints, after putting in the new charge roller had solid (about 50%) background covering the entire page. Complete bust.

Anyone know of any specific vendors where they are cheap (or at least cheap enough) and reliable? I don't mind buying a large quantity if they're sure to be good! Like you, I have TONS of drums that only need a new roller to be resurrected.

It's been a long time since I've had an OPC go bad! It's always the rollers now. But I remember back in the day, the rollers lasted so long that they were still okay by the time the OPC finally pooped out.

[Milo Wilson]

If your IBT and/or the 2nd BTR are not showing any print defects, by all means use them forever. That is usually the only reason to replace them. Make sure to keep them clean though.