[CQ] 470W toner dusting

[acsolutions]

Hello, the w2400 I'm working on had lots of toner built up on the charge assy. on one side only as well as a slight background on the entire print.
I cleaned up the machine and ran it, looked ok then three weeks later customer calls back with the same problem. This is the first time I had seen this machine and I did not know what had been done to it previously. I check the history and saw the charge assy. ID sensor and the developer powder had been replaced within the last 6 months, I could not tell what was causing the charge to get so much toner on it so quickly! I was thinking of replacing the developer again and the seal above the mag roller, I hear this can cause the issue. The customer also said they go through a lot of toner, I'm not sure if it's pulling excessive toner due to calibration! the back grounding had been compensated by adjusting the dev. bias in the service mode. The copies were still a bit weak but customer says this was the best they ever looked. All the toner is leaking on one side. I check to see if the machine was level,OK! when I pulled the toner tube there seems to be more toner and developer on one side. The toner seems to be OEM. Thanks, any suggestions would be great!

[Zia Graphy]

Re: 470W toner dusting

Normally when I've run into toner dusting it has been the drum and/or developer being at the end of its life cycle and needing to be replaced.

However there are quite a few possibilities here. Excess toner ending up on the copies and in the charge unit probably means that there is a problem with the difference in charge between either the toner and the drum or the toner and the developer - or with both. In either case the toner is "falling" off of either the drum unit or the developer roller because there is not enough attraction between the surface of the drum and the toner or the developer and the toner. That's why old developer or an old drum or non OEM toner (with different a charge) are the easiest likely culprits to look at. It's also possible that the charge applied to the developer roller which repels the toner and sends it to the drum is too great, in which case the toner scatters throughout the machine.


Additionally, if there is a bunch of toner in the charge unit it would be worth checking the charge cleaning unit - namely check the foam pads that run along either side of the charge wire. If they are worn out or disintegrated they might not be doing the job and the charge wire would be getting dirty and supplying insufficient charge to the drum which could lead to dusting. Also, you should be able to do an output check of the motor that drives that cleaning unit in SP5804 - check to see if when you activate it do you hear the motor actually energizing.

As I mentioned a bad drum unit could also be causing toner dusting. Those are rather expensive and often people will replace them with a generic alternative. I've had pretty good results with generic drums on the 470W but mileage may vary.

If you've already checked the leveling of the machine I think the seemingly high developer/toner levels on one side of the machine might be a red herring. It's pretty difficult to gauge by hand whether or not one side of that extremely heavy developer unit is slightly heavier than the other. Unless you really notice that one side is empty and the other is extremely overfilled it might just be a perceptional bias.

I would also think about the developer and the toner to see if they were OEM. You really have no way of knowing if the developer was OEM but the toner cartridge should be fairly obvious. An OEM toner cartridge should have a sticker on it listing the ingredients - Acrylic Powder, Wax, Carbon, Contents Partially unknown along with a square with a number inside of it indicating the toner type. I think that machine's toner type is 86.

Finally if there is something wrong with the machine's calibration you should be able to check the settings for developer bias, charge bias, etc in the service modes. See if anything is off the default settings. Another random thought is if there is a problem with the ID sensor you could be getting incorrect readings of the ID sensor patch which would cause the copier to make incorrect calibrations to the development and drum charge which could lead to dusting. This seems less likely because you'd probably get some kind of ID sensor error if that were the case.

Good luck!

[acsolutions]

Re: 470W toner dusting

Normally when I've run into toner dusting it has been the drum and/or developer being at the end of its life cycle and needing to be replaced.

However there are quite a few possibilities here. Excess toner ending up on the copies and in the charge unit probably means that there is a problem with the difference in charge between either the toner and the drum or the toner and the developer - or with both. In either case the toner is "falling" off of either the drum unit or the developer roller because there is not enough attraction between the surface of the drum and the toner or the developer and the toner. That's why old developer or an old drum or non OEM toner (with different a charge) are the easiest likely culprits to look at. It's also possible that the charge applied to the developer roller which repels the toner and sends it to the drum is too great, in which case the toner scatters throughout the machine.


Additionally, if there is a bunch of toner in the charge unit it would be worth checking the charge cleaning unit - namely check the foam pads that run along either side of the charge wire. If they are worn out or disintegrated they might not be doing the job and the charge wire would be getting dirty and supplying insufficient charge to the drum which could lead to dusting. Also, you should be able to do an output check of the motor that drives that cleaning unit in SP5804 - check to see if when you activate it do you hear the motor actually energizing.

As I mentioned a bad drum unit could also be causing toner dusting. Those are rather expensive and often people will replace them with a generic alternative. I've had pretty good results with generic drums on the 470W but mileage may vary.

If you've already checked the leveling of the machine I think the seemingly high developer/toner levels on one side of the machine might be a red herring. It's pretty difficult to gauge by hand whether or not one side of that extremely heavy developer unit is slightly heavier than the other. Unless you really notice that one side is empty and the other is extremely overfilled it might just be a perceptional bias.

I would also think about the developer and the toner to see if they were OEM. You really have no way of knowing if the developer was OEM but the toner cartridge should be fairly obvious. An OEM toner cartridge should have a sticker on it listing the ingredients - Acrylic Powder, Wax, Carbon, Contents Partially unknown along with a square with a number inside of it indicating the toner type. I think that machine's toner type is 86.

Finally if there is something wrong with the machine's calibration you should be able to check the settings for developer bias, charge bias, etc in the service modes. See if anything is off the default settings. Another random thought is if there is a problem with the ID sensor you could be getting incorrect readings of the ID sensor patch which would cause the copier to make incorrect calibrations to the development and drum charge which could lead to dusting. This seems less likely because you'd probably get some kind of ID sensor error if that were the case.

Good luck!

Thanks for the response, the machine has only 34000 feet on the machine so I don't believe the drum is bad yet. I did make a developer bias adjustment, the same as I do on most machines. The setting is usually set at -550 and I take it down to -450, I was having stray toner arcing on the charge wire and this was a cure all, not effecting the CQ. I did the same to this machine after seeing this issue! What I was thinking of doing is taking with me. Developer, cleaning case and auger, Developer seal( the one that sits above the mag roller) and a new toner tube. like you said there could be bad toner. But why is it only on one side, last 8 inches on right side of machine? I checked the gap between the drum and recovery blade, ok. Also checked the auger and used toner delivery section, OK. Your right, about the toner and developer, I need to focus mainly on those! I did initialize the ID sensor checked out OK! Any other suggestions please feel free!

[TonerMunkeh]

Re: 470W toner dusting

Initialising the ID sensor on a worn drum can affect copy quality too, it'll take baseline readings for process control off a drum that is less chargeable than a new one.

[jdzr]

Re: 470W toner dusting

I guess I will stick my two cents in --- Had about the same issue on a new machine some time ago. Come to find out the cleaning auger was compressed causing it to be slightly to short causing the waste toner to back up spilling on the drum and transferring to the charge transfer etc. Re initializing the ID sensor with old developer is not a good idea. If you think the ID sensor is causing a problem simply turn it off in service mode until you can prove if it is the problem. One more thing be sure and wipe down the lens while you have the drum out. probably save you some more grief.
Good Luck

[acsolutions]

Re: 470W toner dusting

Hello, I went back to the machine with a cleaning case,spring auger, upper mag roller seal and replaced developer and calibrated.
everything looked good but after running about 20 prints I saw slight black area (about 1mm) on edge, used toner side. I increased developer bias voltage which made the difference. The machine shows over 30k feet, not sure if this is lanier feet or just standard length! I don't work on these machines frequently! Now I'm questioning the drum! I watched the toner enter the used toner container. After 25 to 30 prints toner is moving to the toner container, the cleaning case was clean when I installed it! What I'm thinking is the drum is so worn the charge is not holding, less charge more toner draw! Not sure if the drum is worn more on one side because toner is accumulating more on that side, but then I thought that the toner cant get out of the machine fast enough! I was thinking about removing the drum and placing the possible bad end on the other side! Not sure! The machine makes great prints, even when I set the developer bias to 400 (originally at 590) at 590 the whole print has a background, I checked the charge setting in the service mode and it looks like the original setting. Thanks for you opinions!

[acsolutions]

Re: 470W toner dusting

I guess I will stick my two cents in --- Had about the same issue on a new machine some time ago. Come to find out the cleaning auger was compressed causing it to be slightly to short causing the waste toner to back up spilling on the drum and transferring to the charge transfer etc. Re initializing the ID sensor with old developer is not a good idea. If you think the ID sensor is causing a problem simply turn it off in service mode until you can prove if it is the problem. One more thing be sure and wipe down the lens while you have the drum out. probably save you some more grief.
Good Luck

I was told th ID sensor was replaced. You had mentioned a lens, I'm not sure where that is?

[jdzr]

Re: 470W toner dusting

When you remove the drum unit right above the drum is the lens. It runs from left to right across the machine and is how the image actually gets to the drum unit. It is a three segment lens. If you had a lot of toner flying around in the machine the lens will tend to collect the loose toner and cause copy quality issues. All it takes is to simply wipe it off when you have the drum out of the machine. I do not recall you saying if you had replaced the cleaning blade but if you did not I would certainly do this also. I would think it would be an extremely remote possibility for the drum to cause the problem as you are describing it although as we all know anything is possible.
One more thing hopefully you did reinitialize everything after replacing the developer?
Good luck

[acsolutions]

Re: 470W toner dusting

When you remove the drum unit right above the drum is the lens. It runs from left to right across the machine and is how the image actually gets to the drum unit. It is a three segment lens. If you had a lot of toner flying around in the machine the lens will tend to collect the loose toner and cause copy quality issues. All it takes is to simply wipe it off when you have the drum out of the machine. I do not recall you saying if you had replaced the cleaning blade but if you did not I would certainly do this also. I would think it would be an extremely remote possibility for the drum to cause the problem as you are describing it although as we all know anything is possible.
One more thing hopefully you did reinitialize everything after replacing the developer?
Good luck

Yes, I did clean those lenses you spoke of, the drum blade was replaced and I had also replaced developer and initialized the developer and the ID sensor after dev. replacment. Thanks