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joelea
11-26-2020, 04:00 PM
Have an issue where mono black prints are coming out fuzzy with white spots. It happens on halftone black 1 pc 255 density but doesn't show up on 64 density.

Tried PRCB, Firmware, PH Unit, HV Unit, Black Drum, Black Dev, PH Relay Board. Have attached a sample in case anyone recognizes the issue.

colour prints where black is made up of CYM is perfect.

4742147422

blackcat4866
11-26-2020, 04:31 PM
Have an issue where mono black prints are coming out fuzzy with white spots. It happens on halftone black 1 pc 255 density but doesn't show up on 64 density.

Tried PRCB, Firmware, PH Unit, HV Unit, Black Drum, Black Dev, PH Relay Board. Have attached a sample in case anyone recognizes the issue.

colour prints where black is made up of CYM is perfect.

4742147422


Did you say what sort of machine this is? =^..^=

joelea
11-26-2020, 04:42 PM
Nope! haha oops , it's a bizhub c224e :rolleyes:

Max
11-26-2020, 04:47 PM
Looks like low toner condition. Whats the toner value? If you add toner manually does the value change? What model? Post a colour test chart. If cym is ok that rules out sep roller. If it doesn't tone up possibly toner supply issue.

blackcat4866
11-26-2020, 04:51 PM
+1. Maybe developer drive clutch? =^..^=

tsbservice
11-26-2020, 06:08 PM
Try to print this tricking the machine thick paper is used and post outcome. I believe but can be wrong that way machine will increase transfer voltages. Or you can try to increase second transfer in service mode.
Also make black test print at 255 density and post here.

allan
11-26-2020, 09:01 PM
Make sure there are no tweaks applied.
Go to image process adjustment and make sure all the settings there are set to default.
Like the TCR values, image background adjust, transfer voltage and density adjustments.

What is the K TCR level?
No C2557 errors?
Any P-codes?

On your own risk hit the devtank with a spoon full of toner and check for a density change.

patrickjlc
11-26-2020, 10:09 PM
Maybe old or bad developer

Sent from my motorola one 5G UW using Tapatalk

wjurls
12-01-2020, 09:45 PM
Possibly an issue with the transfer belt unit? First transfer roller for black not contacting the back of the belt?

REGSIS
12-02-2020, 09:08 AM
+1. Maybe developer drive clutch? =^..^=

With failed developer (black) drive clutch within few prints it will be completly blank because it would prevent magnet roller to turn. But check anyway.

As mentioned above try to swap transfer belt from some other machine 22-36 ppm 4 or 8 series.

Also try to clean PH winodow with a cleaning wand or take PH unit out and clean it manualy.

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