Bizhub 190f image quality issue

[AlGreg]

Hello all,

there is a Konica Minolta Bizhub 190f copier machine at one of the places I work at, and it produces an odd, waterdrop-like pattern upon printing:

bizhub190f.jpg

The pattern fades away after 6-7 pages, and only a faint background remains, but it comes back after a few minutes of rest.

I already cleaned the drum unit and the fusing unit but it did not help whatsoever.

The machine is only 1 year old and it has cca 5.000 impressions in it.

Thank you&bye

[kingarthur]

Re: Bizhub 190f image quality issue

think this is normal on this model when the toner is low & needs changing

[AlGreg]

Re: Bizhub 190f image quality issue

think this is normal on this model when the toner is low & needs changing

So it makes dark areas because it is out of toner?

Then why is that the pattern thins out after a few pages, but the page content remains good?

Besides, according to the manual the yield of the toner cassette is 16.000 pages, and this unit has only 5.000 pages printed. (Of course the vendor could reset the counters but I do not think he did)

Sorry, I do not intend to doubt your knowledge, but it just does not fit into my head.

[kingarthur]

Re: Bizhub 190f image quality issue

the counters have not been reset, there is probably a starter toner in there, which a lot of machines have just to "start" you off, also, the 16,000 pages per cartridge you'll never do, it is rated at 5% coverage of the page...nobody does 5% coverage, it is a lot more...nobody ever gets 16,000 copies out of 1 toner....it's like your car...if you drive it in the town you'll get a lower mpg than if you drive it on a motorway....if you have another machine swap over the toner cartridge...

[minimerlin]

Re: Bizhub 190f image quality issue

Kingarthur has hit this on the head...it is caused by the toner cartridge, happens all the time on these beasties!

[blazebusiness]

Re: Bizhub 190f image quality issue

Kingarthur has hit this on the head...it is caused by the toner cartridge, happens all the time on these beasties!

Agreed,very common failure, don't doubt his knowledge even if it doesn't fit in your head .....toner,toner,toner!

[AlGreg]

Re: Bizhub 190f image quality issue

Agreed,very common failure, don't doubt his knowledge even if it doesn't fit in your head .....toner,toner,toner!

I was finally able to aquire some toner, refilled the cartridge then lo and behold: it worked

So first of all I bow before your knowledge, but could someone please tell me the physics behind this phenomenon? These machines are fairly uncommon in my country, and every copier machine with low toner I met produced white streaking/faint printout.

The other thing that added to my confusion is that the cartridge still had about 30 grams of old toner, and the low toner warning did not went off as well...

Anyway, thank you again for your help!