Canon it 7105 light CQ

**mxm** · 03-04-2014

Hi
Does any one have any ideas for fixing light CQ on a canon ir7105

Here is a sample of the fault (image generated from fiery) (test print)

I have changed the following
We are using katun toner
Changed main, transfer/sep & pre transfer charge units
Changed high voltage pwb
Changed high voltage connector block
Changed transfer/sep hv transformer
Changed image density sensor

here are some pics of the charge setting

**V-P** · 03-04-2014

VL1-T & VL1M are in different ZIP codes.

Except for the standard answer of the OEM Toner - I would check the laser.

**zoraldinho** · 03-04-2014

Did you visually check drum surface or developer cylinder?

**tinnyjay** · 03-04-2014

Originally Posted by zoraldinho

Did you visually check drum surface or developer cylinder?

I am working on IR7105 from 2 years and i think your problem comes from non genuine toner and its just bad transfer problem.
First,to be sure,you must clean laser protection glass and go to SP-FUNCTION-INSTALL TONER and press OK.
Let the copier to finishish the process.
Make a print from computer to locate the problem,if it comes from engine or from the scanning section (mirrors etc).
If nothing changes, remove transfer/separation corona and change wires.
Also, clean other coronas well with alcoohol.
You will se that everything will be ok

PS-If nothing changes, remove developer unit, vacum the toner inside and use genuine toner.
You think that you are saving money using katun toners but believe me that you are losing more than using genuine canon toner.

**mxm** · 03-04-2014

Hi thanks for quick response

I have 2 ir 7105 in the same room both using katun toner one is ok.
swapped dev unit from good m/c no difference. And bad m/c dev unit ok in good machine.
visual inspection on the drum is fine had new dm 500 k ago, machine done 6.8 million in total

To change the laser is it optics section off to remove (will look in manual)

will lookup in manual and try your suggestion tinny jay

**aco.bk** · 03-04-2014

I think that problem is in potential control.Try to disable po-cnt in service mode COPIER> OPTION> BODY> PO-CNT (enabling/disabling potential control)0: potential control OFF
1: potential control ON (default).
potential.jpg
and try to increase density level. copier-adjust-dens.

**mxm** · 03-04-2014

Originally Posted by aco.bk

I think that problem is in potential control.Try to disable po-cnt in service mode COPIER> OPTION> BODY> PO-CNT (enabling/disabling potential control)0: potential control OFF
1: potential control ON (default).
potential.jpg
and try to increase density level. copier-adjust-dens.

Have tried that, even replaced potential sensor.
thanks for taking the time to help.

**tinnyjay** · 03-05-2014

Originally Posted by mxm

Have tried that, even replaced potential sensor.thanks for taking the time to help.

Canon found a laser problem on this machine after it was in the market and they developed a new upgraded laser unit to solve the problem.Everyone knows this machine, probably think your problem is related to laser unit, but believe me that the real problem of this machine in general is only tranfer/separation corona.In your case, i would vacum well developer unit because using katun toner for a long time, makes toner inside looks like a hard rock.