No Magenta + Error P-7 , P21 and P-28

**Jamil Mungur** · 10-13-2015

Hello
I have a Bizhub C224e with print quality problem.On my first intervention there was error code P-7, P-21 and P-28 and also an uneven magenta background on all prints.
Replaced the Magenta Developing unit and also the drum unit. Now the problem is that the machine is not printing magenta. The other colors are ok.

Printed the color pattern, the black is ok but all the other colors are not good. I attached the prints.The toner concentration seems ok for all 4 colors and also the IDC sensors.
Removed and fixed back the High Voltage pcb but the problem is still the same.
When i put back the old drum and old developing unit the problem is still the same.

Did a manual toner add in service mode but problem is still the same.

**copier addict** · 10-13-2015

Try a new transfer belt. I see you have a mark on both the black and magenta gradation patterns.
And clean the IDC sensors.

**MARDSO** · 10-13-2015

I already got problem in laser flat cable! wipe his contacts

**allan** · 10-14-2015

The diagonal lines on that sample print for magenta shows low developer. But does not seem to be your problem.

**Jamil Mungur** · 10-14-2015

Hello

I will try to clean the contacts of the four lasers and also i am planning to test with a new transfer belt.

Allan i do not understand , please explain to me.
The diagonal lines on that sample print for magenta shows low developer. But does not seem to be your problem.

I will keep you all updated.
Thanks

**Jamil Mungur** · 10-14-2015

I replaced the Transfer Belt and also cleaned the contacts the laser units. Problem is still the same. The diagonal lines on the prints are also still here.

**allan** · 10-14-2015

If you remove the developer tank you will see that pattern on the mag roller.

**tech51** · 10-14-2015

I suspect your Hv board has failed causing dev to be depleted from the unit.
You say you have removed & fixed back the Hv but not replaced it.
You will have to replace the dev unit again.

**Jamil Mungur** · 10-15-2015

Is there a way to test the HV board ? I do not have a HV board in hand so i will have to order it. I want to be sure before ordering so i want to test the HV board.

**allan** · 10-15-2015

No not if you don't have a proper test bench, some of the voltages are too high for a standard tester.
How to get to test points on the grid, scorotron and dev bias?