Ar-m350 / 450

[hollisizer]

Wow im tryin to get my hands around this one...we have alot of these machines out there and im gonna go out on a limb...

1) same symptoms on numorous machines

2) black streaks around the same time on all machines that come and go

3) PM kits installed among many other parts

If it were static problems I dont think it would be on so many machines around the same time.

We had a similiar problem with black streaking around the same time on a few machines in a technicians territory. Around 400k to 500k black streaks would come and go throwing all kinds of Pm supplies at the problem with no result. Come to find out the dv bushings were not being replaced by this tech causing bad drum crush pressure between the drum and the dv unit.. this was immediately solved by replacing the entire Developer unit on both machines.(was less expensive to buy the whole unit than the parts needed to rebuild)

Like I said just goin out on a limb, I keep hearing about paper dust and just wonder if were stuck in a theory.

Try replacing dv unit?

[jpcopy]

on the 350/450, what dev bushing are you refering to? I can't find in service hand book. I am having problem with dev units with more than 300k now. I get background on first side thru. about a third of the page on the front side as exiting on the left. it appears the mag roller is out of round so to speak. background darken at a high spot. problem follows the dev unit when going to another machine. doesn't do it on second past thru when duplexing. does much worse with 11X17. It's like the dev unit is loosing bias on operator side. I'd say the unit with 3 to 500k do alright with using letter only but some of them will back ground on long runs. I have tried dev units with under 300k and they are not having this problem even on 11 X 17. this is the reason I asked.

[choicecopyguy]

on the 350/450, what dev bushing are you refering to? I can't find in service hand book. I am having problem with dev units with more than 300k now. I get background on first side thru. about a third of the page on the front side as exiting on the left. it appears the mag roller is out of round so to speak. background darken at a high spot. problem follows the dev unit when going to another machine. doesn't do it on second past thru when duplexing. does much worse with 11X17. It's like the dev unit is loosing bias on operator side. I'd say the unit with 3 to 500k do alright with using letter only but some of them will back ground on long runs. I have tried dev units with under 300k and they are not having this problem even on 11 X 17. this is the reason I asked.

Check the mag roller for toner buildup, a good cleaning with a 3M pad will resolve this, just don't scrub too hard as it will worsen the effect down the road.

[ZOOTECH]

To add to choicecopyguy's post, when the dv has been removed and mag roller cleaned and vacuumed, check the doctor blade gap at .45mm plus or minus .03mm.

[jpcopy]

did the scrub pad thingy and did a developer change with it. same as befor doing it. as the doctor blade I see no adjustment. I didn't ck gap for that reason. if its out do you chunk dev unit and buy new? anybody got good prices on them.

[mnm]

Well I'm all for thinking outside the box at this point. Maybe this paper dust issue is just fallout from a broader issue, I just can't put any logic to it as of yet. Meantime I went ahead and ordered a new DV unit ($77 through Precision Roller) and we'll throw that at it a see if it sticks.

[jpcopy]

mnm
keep us posted as I would like to know for future ref.

[hollisizer]

I am referring to the mag roller bushings...they hollow out causing the mag roller to move around and will give changing docter blade gaps... will cause intermittent background, black streaks, toner buildup in drum unit and interior of machine. We are changing mag bushings around 200-250k or just replace entire unit the price is pretty reasonable.

[jpcopy]

hollisizer
I think you have something there. wiil have to put some bushings on order, and a few dev. units

[mnm]

Well my friends, It looks like we have cured the ailing 350's and 450's. I had mentioned a while back that we had noticed some dust buildup on an ozone filter in the transport...it's tucked away in there in front of a suction fan. We tried cleaning it with no luck. We tried to order a replacement but Sharp shows it as a "non-serviceable" part. So in a moment of desparation and frustration we just ripped the dang thing out (it's glued in). Lo and behold...we have been running the machines for over a week with nary a paper dust issue. We have applied the same rip-and-tear to the other machines and they all seem to be responding rather well finally. So after installing several paper dust remover filters, drums, blades, transport units, dv units and countless hours of labor the solution was to remove a little 1"x8" ozone filter that you can't hardly find and can't replace. The obvious theory is that with the filter new and clean...or removed....that the suction fan draws out enough of that paper dust from the transport and keeps it from mucking up the drum blade. Who would have thought?