Canon C7010 - Weak Black

[neoboy3000]

Hi, folks - I've got a C7010VP that has weak black in the prints. I had swapped the entire PCB (1-1,1-2, and 1-3) rack to resolve a different issue, and have gone back over those one at a time to make sure that the issue isn't with the boards. I can switch the entire P-kit and the issue remains. If I swap the K dev unit the prints are dark for a while, but then it fades again. When I put the K dev unit into another machine it takes the weak prints with it, which makes me think there's something with the toner/dev mix maybe? I installed a new K dev unit and developer, and it held for about a day and then faded out again.

When I perform a grid-adj the black is weak or even completely absent, which had me chasing the charger for a minute but when I saw the problem follow the unit to the other machine I abandoned that route. I also swapped and checked out the environmental control board and the K potential control board.

I'm considering the controller box assembly next. I did at one point swap the video cable for the K writer, but the black being absent from the grid adjust with the laser not writing makes me wonder. I suppose I should swap that back to rule it out. If anybody has any bright ideas on it I appreciate the help. Thanks.

[Phil B.]

Re: Canon C7010 - Weak Black

Hi, folks - I've got a C7010VP that has weak black in the prints. I had swapped the entire PCB (1-1,1-2, and 1-3) rack to resolve a different issue, and have gone back over those one at a time to make sure that the issue isn't with the boards. I can switch the entire P-kit and the issue remains. If I swap the K dev unit the prints are dark for a while, but then it fades again. When I put the K dev unit into another machine it takes the weak prints with it, which makes me think there's something with the toner/dev mix maybe? I installed a new K dev unit and developer, and it held for about a day and then faded out again.

When I perform a grid-adj the black is weak or even completely absent, which had me chasing the charger for a minute but when I saw the problem follow the unit to the other machine I abandoned that route. I also swapped and checked out the environmental control board and the K potential control board.

I'm considering the controller box assembly next. I did at one point swap the video cable for the K writer, but the black being absent from the grid adjust with the laser not writing makes me wonder. I suppose I should swap that back to rule it out. If anybody has any bright ideas on it I appreciate the help. Thanks.

well you never mentioned:
compat toner?
life on drums?
I assume you cleaned laser path glass/lens?
are you calibrating the swap units each time?

[neoboy3000]

Re: Canon C7010 - Weak Black

well you never mentioned:
compat toner?
life on drums?
I assume you cleaned laser path glass/lens?
are you calibrating the swap units each time?

OEM Toner
Have tried different drums and drum assemblies, including new ones - as I said I switched even the entire P-Kit from a working machine
I am looking again at the laser now, but yes, the path and glass are clear
Yes, calibrating after swapping units. DPC, server shading correction, auto gradation, color calibration.

I said I would try the video cable for the K laser, since it had been swapped before, that did not resolve the issue. Going to look closer at the laser unit again, I have spare machines to swap parts with for troubleshooting.

[neoboy3000]

Re: Canon C7010 - Weak Black

Swapped the writer, no change. Wondering if toner concentration has anything to do with it, since the problem seemed to follow the dev unit to the other machine. As if the mix inside of it wasn't good. Looked like toner is getting through, will look into it.

[neoboy3000]

Re: Canon C7010 - Weak Black

Looking through settings for clues, found that the patch detection at ATR control - Lv 2 COPIER>DISPLAY>DENS-S-K - is reading at 542, but the value of the target - Lv2 COPIER>DISPLAY>DENS>D-K-TRGT - is set to only 365. The other three colors are around 360 and are reading normally. Tried swapping the whole black P-kit again to test a different patch and potential sensor, but no change. Going to investigate this route more. It has something to do with the density control, maybe the toner concentration.

Thanks to anybody watching the thread, trying to think out loud on this one.

[tbyabachwezi]

Re: Canon C7010 - Weak Black

Looking through settings for clues, found that the patch detection at ATR control - Lv 2 COPIER>DISPLAY>DENS-S-K - is reading at 542, but the value of the target - Lv2 COPIER>DISPLAY>DENS>D-K-TRGT - is set to only 365. The other three colors are around 360 and are reading normally. Tried swapping the whole black P-kit again to test a different patch and potential sensor, but no change. Going to investigate this route more. It has something to do with the density control, maybe the toner concentration.

Thanks to anybody watching the thread, trying to think out loud on this one.

Do you have service manual for this machine?

[neoboy3000]

Re: Canon C7010 - Weak Black

Do you have service manual for this machine?

Yes, I've been trying to read through it in regards to this issue.

[tbyabachwezi]

Re: Canon C7010 - Weak Black

Yes, I've been trying to read through it in regards to this issue.

Ok good to know if you have the service manual. But any success? You are getting weak print only in black? And have you tried to toner up?

[neoboy3000]

Re: Canon C7010 - Weak Black

Ok good to know if you have the service manual. But any success? You are getting weak print only in black? And have you tried to toner up?

The only success I did see was when I changed developing assemblies it was normal but then faded. It is only in the black, yes. I'm not sure where the control is to adjust the toner amount, but I did have the idea of trying to adjust it. I was getting ready to look for it in the service controls menus of the manual but got pulled away to replace some drive components on another machine that were more urgent. The other idea I had was bad toner, but I think it's more how much toner is being mixed.

Thank you for the replies, it's much appreciated.

[tbyabachwezi]

Re: Canon C7010 - Weak Black

The only success I did see was when I changed developing assemblies it was normal but then faded. It is only in the black, yes. I'm not sure where the control is to adjust the toner amount, but I did have the idea of trying to adjust it. I was getting ready to look for it in the service controls menus of the manual but got pulled away to replace some drive components on another machine that were more urgent. The other idea I had was bad toner, but I think it's more how much toner is being mixed.

Thank you for the replies, it's much appreciated.

Ok but if you think the toner is not good then go ahead and change it, if problem still there let us know but also it could be the problem with the way toner traveling to the developer. Coz you said if you change the dev print dark for sometime then fainted it could be due to lack of toner inside developer try to add some toner to the developer manual then see what happen

[neoboy3000]

Re: Canon C7010 - Weak Black

Ok but if you think the toner is not good then go ahead and change it, if problem still there let us know but also it could be the problem with the way toner traveling to the developer. Coz you said if you change the dev print dark for sometime then fainted it could be due to lack of toner inside developer try to add some toner to the developer manual then see what happen

Ok, I'll give that a try. Thanks.

[neoboy3000]

Re: Canon C7010 - Weak Black

Do you know if there is a software control for manually adding toner, or do I need to physically remove the dev ay and pour it in while turning the gears?

[tbyabachwezi]

Re: Canon C7010 - Weak Black

Do you know if there is a software control for manually adding toner, or do I need to physically remove the dev ay and pour it in while turning the gears?

I know there is a sensor which control amount of toner in the dev but there range of voltage so by not adding too much it will be ok.

[neoboy3000]

Re: Canon C7010 - Weak Black

Ok, so I found the controls in the service software to adjust the upper and lower toner target densities and have been playing with them a bit. I managed to get the prints to come out much darker than before, though maybe not quite 100% just yet. I read in some service notes to try running a couple hundred copies after changing the setting to allow the adjustments to take effect and it seems to be working. Might still try adding a little toner manually to see if I can perk it up some more, but for the time being we'll try running some less sensitive jobs on it and see if it continues to improve. For the record, the settings I adjusted are

Lv2 - COPIER>ADJUST>DENS>HLMT-PTK (upper target density)
Lv2- COPIER>ADJUST>DENS>LLMT-PTK (lower target density)
Pages 18-145 and 18-146 of C7010 service manual version 6

[Wilson101]

Re: Canon C7010 - Weak Black

I don't know if your issue is resolved now but I think it has to do with a blockage in the black hub unit. It is not supplying enough tonner into the developer to print strongly.
Remove the black hub unit to make sure there is no blockag. Also you for the mean time manually fill the developer unit with some of the tonner but it will fade again when it is used up.