Konica 7272 dropping developer

[methogod]

just a line about .5 inch or less across the top of regular 8.5x11 paper (LEF). Changed DV units, changed PM units, adjusted voltage...

Still will run clean for 3000-5000 copies then it appears, looks like a buildup of toner on the grid, once clean, will again run 3K-5K clean.

I am swapping charge units off another machine today, ill post if that fixes, but I am at a loss, machine has total of 780K, its all printing no copies.

Aways prints from LCT, face up. Rollers are new, PM is new, drum is new.

Any ideas...

[TonerMonkey]

This is an old old problem which hasn't really been resolved by KM, I think it's because of recirculating toner but all sorts of workarounds have been tried to sort it like inserting conductor between the dev bias contact and mag roller, changing mag angle, restatrting machine and cleaning all toner out of process section etc etc but without much success.

Maybe someone else has had more success but as far as I know it's one of those problems that doesn't affect every machine nor has a definite solution.

[methogod]

Like I said, I have does all this, didnt change the mag angle or anything but i have 6 other 7272/7255 and never had this issue.

[TonerMonkey]

get the message although I thought you might like the benefit of someone having worked on hundreds of 7272's and not being able to find a solution but when you find out what it is be sure to let KM know because they don't seem to have a solution for it either.

If you're having trouble with this issue then keep your head up if you don't find a fix for it is the point I'm trying to make.

[RRodgers]

One thing to do is be sure to vac out the ducting for the dev unit. (fan on the right side of the machine has a filter, vac that out)

[copycommerce]

Check the drum and be sure to use original toner(the Katun one fucks up the inner parts of the dev box).I was having the same problem with Bizhub600,after replacing the drum and the developer the things went to normal.

[methogod]

My copier guy is great, so i'm sure between your suggestions and some bearings he suggested we will figure it out.

Worst case it becomes a parts machine, and I get a new 1050e or 920.


thanks,

[methogod]

I have the solution, turns out the drum bearings were ARKing out, a bit of conductive grease and a proper cleanign did the trick.

Ordered all 4 bearings and the drum shaft, will post if it comes back....

[907tec]

Hey Methogod, what kind of conductive grease are you using? I've been looking around for something similar, but have come up completely empty. Plenty of thin, spray-on contact cleaners or dielectrics, but no real conductive grease. I'm guessing it's some sort of thick graphite-type grease that you can pack into the bearing raceways?

[copyplus]

I am also having the toner/developer dropping problem. Also when the page is printed it comes out grey (the whole paper is greyed out, like a grey background). Any solution? Pl note that I have already poured new developer in the unit and using original toner and developer. Cleaned in and around the developer unit and grids.

[methogod]

GREY PAGES, sounds like main charge, i would replace the charge wires first. If they have more then 1 machines, i would swap parts before spending money on a full PM kit. IF that doesnt do it, I would look for some shorts. I have seen conductive gresses fix a bunch of odd issues like this. If there is dev at the top of bottom of each page - THEN ITS A CHARGE GRID ISSUE.

NEED MORE INFO ON METER AND COUNT OF MAJOR SUPPLIES.

[copyplus]

The machine has only 59000 copies on its counter. The developer is just changed. Cleaned all the grids and they seem to be ok. the grey backgound prints on the whole page not a particular area. They start from about 5% grey to 50% with number of copies printed. Suppose I start printing the first copy comes out clean and then after making 10 copies it starts 5% grey and then at 200 copies it is 50% grey and so on....

[methogod]

can you email me a scan of the 1, 50th and the 200th.

cant really tell if you have a image being produced or not. If its jsut grey, no image, it has to be somthing with the charge/transfer units.

[copyplus]

I don't know if you will be able to see the scanned copy. The text and graphics printed are ok. Just grey background (like a dirty print). I can email you the copies - what is your email address.

[methogod]

m-scudder@comcast.net

[copyplus]

Sorry, I try to scan but the scanner did not pick up the background. It is like a grey dust in the background which gets darker. When turn off the machine and start next day it starts printing ok but after some copies it starts printing grey dust in the background. Maybe I will change the drum and cleaning blade next week and see if it improves. I am really grateful for your kind help.

[copyplus]

Thanks methogod. I changed the drum and cleaning blade and new developer. All the problems are solved. No dropping toner, and grey backgrounds. Thanks a lot.

[methogod]

IF you know a dealer who will sell at cost i need parts - having some trouble getting KM items at cost.

Especially items for my C451

[copyplus]

I am back again with the same problem of toner dropping in my KM 5510. The toner drops on the bottom grid especially more on the back side than front side. At 65000 I changed the drum, developer and cleaning blade and the problem was solved. Now at 104,000 I have the same problem. I changed the cleaning blade and the problem still exists. I also cleaned the filter. What is service cycle of these machines. Do I need to change the drum and developer again? Or there is any other solution to this problem. This is the worst copier I have seen my life.

[methogod]

We had the same issue, try some conductive grease on the back of the drum, where the drum makes metal contact to the rear of the machine. It didnt take much but we had this issue for a while, tried alot to fix it. Other time it was just consumables or other issues with parts.

What is the meter count?
What is the PM count? Drum Count Dv count?

What stock are they printing on? are they printing volume.

The 7255 or your version of it, has some known limitation, its not meant to be a production machine, the heat will cause other failures.

What is the count on the DV unit?

Are you using OEM everything? Toner? Drum? Etc...

Have you gone though the adjustments, HV adjustments, Drum Perc, etc.

call me if you want to go over this step by step you have to eliminate the most common issues first.

[copyplus]

Thanks Methogod
I applied grease on the drum and it is much better now. Appreciate your help.

[methogod]

Glade you found the issue, becuae trust me that is a shot is the dark. Had a machine down in my product enviroment for month with this issue.


honestly if hate the developer issue its time to move to a 750/920/950, depending on your needs. The older models drop developer, the newer ones do not have nearly the same number of issues.


thanks,

[MBMCO]

Just throwing my 2 cents into the hat.

Have a C364.

Round 1: In one day all 3 color drums dropped their life count to 0. Customer never called and said the warning display had popped up which WAS turned on to display. The drums were done. Locked up the machine so it couldn't print because they were out of their life (BTW there is a way to bypass that only for experienced techs). Replaced all 3 drums. Made test prints. Color copies were light shaded and streaked for Magenta and Cyan. All copies had 2 large colored streaks on prints. See attachment.

Round 2: Magenta and Cyan Developers were splotched. Bare random spots on roller. Thought the developer wasn't charging well (both?). Adjusted BIAS VOLTAGES around a bit without success. Figured out there was about half as much developer in the units than there should be. Went looking for the developer. Waste toner bottle was at least 50% developer. Put a magnet inside and it was covered. Dumped it into a bag and tested it through the bag and was shocked at how much developer was in the bag. Magenta and Cyan were dumping developer.

Round 3. Large Streaks. Transfer belt cleaning blade and toner auger shell was PACKED full of toner and developer also. Packed so full it was leaking out of the edges causing the streaks. Removed that from transfer belt and cleaned it out. Cleaned up the streaks.

Round 4: Good drums, clean transfer belt, clean copies still Magenta and Cyan problem. Justifying 2 color developer units to my employer on a copier that only had 88k color copies run through it was a tough sell (500.00 ea). Developer powder only sold separately aftermarket.

Big question though is why did 3 drums go at once, transfer belt get so plugged up and 2 developer units lose so much all in one shot? Traced all down to the developer units dropping developer and passing it throughout the system.

Hence all of this was the vicious circle of a day of a C364.

Transfer belt dumping toner out the sides, toner covered rear inside of machine, bunged up developer unit contacts, developer units not charging well, developer not adhering to roller well and passing onto drums and transfer belt, plugging them up further causing more spillage and so on and so on.

As it sits now we are cheaping out and going to try and fill the developers back up to normal level. Figure if we destroy them with aftermarket stuff no big deal we may have to buy new ones anyway. Everything else is working great for now. Will update after it has all been running a bit.

That's my story. I hope this helps out someone because it drive me into madness.

[MBMCO]

UPDATE:

I replaced the developer powder in both units which worked great. The reason for the developer dumping is still a mystery at this time but I am monitoring it to see if the developers themselves are bad or if the new powder will take care of the issue.

Either way customer is happy and all is well with that unit. Save my employer 800.00 too so he is somewhat happy although I doubt I hear anymore about that savings.