background in back side of the image

[aaahmmm]

Dear all

According to my last thread about Dirty background on MP7500 on the back side of the image. as I siad I have 4 same machines 2 of them starts to have back ground after 50 – 100 k , and the other 2 starts to have background after 200 – 250 k .I know replacing the transfer belt and blade solve the problem but for a while.

I tried to use original transfer belt and blade and KATUN brand It still have the same . also I install old transfer belt and blade with about 600K life ( from my old 1060 machines) and the dirty background yes it is worst but it is not that big different from the 200k life belt.

Do I need to adjust something or change some parameters like transfer current or …….. I don’t know. please I starts to hate mp7500 because of this , i cant replace hte transfer after 100Kor 250K , in old 1060 some times I did more than 700k on the belt.

[Counsel]

What do the transfer belts look like after the machine starts causing the dirty backs, are they covered in toner or look more worn then usual. I have had transfer belts go 800k-900k before on this model machine without problems. I don't think changing any settings is going to fix the issue, the only reason for dirty backsides is that there is toner or build up in the transfer area that it attaching to the back of the page, if the belt was clean voltage setting wont pull toner through the paper onto the back the toner has to be there already. When you replace the belts do you clean the metal rods that the belt slips over make sure they are nice and shiny, then clean all the waste toner out from the blade area, and clean the the inside of the transfer deck. One thing mentioned which I doubt is the issue but doesnt hurt to check is the paper size settings, make sure they match the trays in the user tools>system settings, if smaller paper is going through then what it thinks the drum will have toner outside the paper area leaving it on the transfer belt. Also check your drum cleaning blade, any left over toner on the drum after the paper passes by is getting put on the transfer belt. I would clean the whole PCU section up, make sure the felt or spongy pads that keep toner from blowing around are all in good shape, and your pcu filter, and developer filters are sealed in and not scrunched up letting dev or toner blow around.

I know the when the sponge or felt pads are worn in areas it lets toner dust through the machine, there should be a filter between the drum and fuser section that long black plastic one clean that or replace it. I think your issues are caused by dusting which is covering the transfer belt with toner.

[blaze2000]

Verify that all settings are correct especially toner density. Your getting toner dusting, so you possibly have a ventilation (or lack thereof) issue, check the machine locations, fans and filters. Your HV board could be a possible suspect as well.

[vargue]

try to use another toner if yo use refill toner be certain that working good

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[aaahmmm]

The transfer belt look normal when it starts to make background . I starts to believe that its toner dusting I found toner under the duplex unit , but if its dusting why I just found background in the back side logically I should found background in the front side also?what could produce the dusting? I check all the filters and the ventilation its looks normal.Another question how can I clean the black cleaning roller of the transfer unit?

[Counsel]

If your getting a lot of toner build up under the duplex unit make sure that the waste line isnt clogged, the transfer deck should slide into a hole at the rear where it augers out the waste that is cleaned off the belt, if that is clogged its backing up and dropping toner on the belt and down to the duplex you notice this on the rear side of the duplex tray all the back will have toner and if you remove the duplex tray and look in the back you will see a pile of toner just below where the transfer belt unit sits, I usually suck out that line when I PM the transfer belt and blade.

As far as that cleaning roller I guess i am not sure because I usually just take out the belt and blade and vacume it all out never had to really clean that roller much, replace blade, replace belt. Suck up the toner and make sure the waste line is clear and working. Most of my transfer belts on these go almost double the PM they recommend.

[aaahmmm]

It is not toner build up it is like dusting under the duplex unit , I checked the waste line before it was ok and working well.