Bizhub pro c500 - white spots on black color. Please help

[jakobsy]

Black color on the printed sheet looks as if it was not enough toner, there are white spots, low density. How do I add manually to the black toner developer unit is in a while is OK (around 200-300 pages) and then do the same. Can someone help me?

[RRodgers]

Are you a end user or tech? If you are a tech, clean the charge corona and then run number 21 (all 4 of them) in the key op mode. That should take care of it. If you are an end user, just go into key op mode (if it's enabled) run all 4 in number 21.
HTH

[jakobsy]

Corona is OK. Have not yet checked key operator mode 21, but take a look (for a few days). I put on another developer unit, and nothing has changed, but I'm not sure that is good. I have a question: how to increase the amount of toner in the developer unit?
If there is a lot of toner in the developer unit is all OK.

[mrwho]

I would check the bias connection for the black developing unit.

[jakobsy]

Where can I find out, in 47 mode (09-03)? What is a good value?

[mrwho]

Bless you!

EDIT: This probably doesn't make sense for those who didn't read Jakobsy's original reply.

[jakobsy]

sorry for the mistake, I use the translator

[mrwho]

As for the bias, I really don't know offhand what is an acceptable value, I was talking about checking physically the bias connections.

Anyway, some tips from the troubleshooting guide:

- Possible causes:

a) Due to developer deterioration, developer charging level increases and the image density on the drum decreases. It tends to occur with 5% or lower
coverage print. (Go to Basic solutions B-a through B-c.)

b) The density is low since the toner density is low. (Go to Basic solutions B-d.)

c) As the first transfer condition is not appropriate, transfer failure occurs and the
density decreases. (Go to Basic solutions B-e.)

- Possible Solutions

a) 1. To resolve developer deterioration, perform the toner refresh mode in the key
operator mode. (up to three times)

2. If it is not resolved by the manual toner refresh mode, output seven A3 solid
pages from the 36 mode internal pattern in the affected color with customer’s
consent.

3. If the key operator mode, 13. Memory switch, 49. Color gamut is set Normal,
change it to Wide.

b) To check the toner density, perform the 47 mode 50-P12 through 15.
1. If the value is 180 or less, check the toner bottle rotation during printing.
2. If the bottle is not rotating, repair the toner supply unit.
If the value is more than 180, replace the developer.

c) Adjust the first transfer current in the 36 mode, 1. Process adjustment, 1. High
voltage adjustment, 1. First transfer current adjustment within a range between
-45 and -30μA.
However, too large and too small values are both NG.

[iust]

C500 overMore K color !!

hi
I have opposite problem . when I print a page that has black background , in result at black area , color is burned and given out on page so as discontinuty occure on image .
I decreased black density in OP key but has not affect. PLS. HELP ME