Lexmarl C748DE No Red at all

[Lance15]

Re: Lexmarl C748DE No Red at all

Photoconductor Unit

Start with that. More than likely the problem.

[Dave]

Re: Lexmarl C748DE No Red at all

Did that, no change.

[Lance15]

Re: Lexmarl C748DE No Red at all

40X6401, 40X5096, 40X8307 - Lexmark C734 Transfer Module, IT Item Inc.


Transfer Belt (ITU). Possible faulty charge roll under the belt for magenta.

[Dave]

Re: Lexmarl C748DE No Red at all

Very plausible. I will swap the roller.

40X6401, 40X5096, 40X8307 - Lexmark C734 Transfer Module, IT Item Inc.


Transfer Belt (ITU). Possible faulty charge roll under the belt for magenta.

[Phil B.]

Re: Lexmarl C748DE No Red at all

I am quite sure the toner is new, have you seen issues like this with these magenta toner units right out of the box? Just to clarify, there is toner on the mag roller. When I wipe a small area on the mag roller with a clean, lint free cloth, it goes away when the motor turns on after the door is shut. The machine runs, no trouble codes. I have the transfer belt unit out of the machine and am going to go over the magenta transfer roller and connections with a fine tooth comb. If I do get to the point where I replace the toner I'll probably just send the machine to surplus. Also, what is the procedure for printing out the "quality page"?
Thanks!!

ARE THESE OEM or compatible toners?

[Phil B.]

Re: Lexmarl C748DE No Red at all

do you have a menu option i service mode to be able to SWAP toners? ( like HP DISABLE cart check? )

have you checked laser shutter?

my guess compat toners... bad transfer ( if ROS is not the issue )

[Lance15]

Re: Lexmarl C748DE No Red at all

The laser in this model is a block like the 3600/3800/CP3505 machines. They don't have the shutters to keep the glass clean. Never thought about aftermarket toner considering all explanations only seem to point to magenta. My guess would be the charge roller underneath the belt associated with magenta. Have never seen where you can only order a charge roller. Gotta replace the whole belt.

[Dave]

Re: Lexmarl C748DE No Red at all

I did a stop test and I have no magenta on the drum. I found out today that the magenta cartridge is definitely new and genuine Lexmark brand. I also swapped the drum again and cleaned the ground contacts for it. Also found the test for the toner sensor and that is changing state as it should. I’m still researching the manual because it feels like there is something particular to lexmark or this model that I am not aware of... I’m not sure changing the transfer belt will help, there didn’t appear to be anything there to transfer. It could a bad laser but there no errors logged. More later

The laser in this model is a block like the 3600/3800/CP3505 machines. They don't have the shutters to keep the glass clean. Never thought about aftermarket toner considering all explanations only seem to point to magenta. My guess would be the charge roller underneath the belt associated with magenta. Have never seen where you can only order a charge roller. Gotta replace the whole belt.

[Dave]

Re: Lexmarl C748DE No Red at all

Thanks and I appreciate all the valuable and thought provoking input. I do not have a spare transfer belt unit and I don't want to pop for a new one so I am going to take the belt and rollers off the unit, clean it, and when I put it back together I will swap the magenta transfer roller with cyan or yellow. I'll keep you posted.
Lance15, do you know if I should see an error code on this particular model if the laser does not turn on? Is there a beam detect sensor on this model?

[Dave]

Re: Lexmarl C748DE No Red at all

I jus found this in the manual. It looks like it enables cartridge swap.Enforce color order LEXMK.jpg

do you have a menu option i service mode to be able to SWAP toners? ( like HP DISABLE cart check? )

have you checked laser shutter?

my guess compat toners... bad transfer ( if ROS is not the issue )

[Phil B.]

Re: Lexmarl C748DE No Red at all

I jus found this in the manual. It looks like it enables cartridge swap.[ATTACH=CONFIG]41948[/ATTACH]

there ya go.. enable .. switch carts... see if problem travels to the new spot

[Dave]

Re: Lexmarl C748DE No Red at all

The problem did not move with the cartridge. Correct me if I am wrong, transfer issue or Laser issue.
Thanks!!

there ya go.. enable .. switch carts... see if problem travels to the new spot

[Phil B.]

Re: Lexmarl C748DE No Red at all

The problem did not move with the cartridge. Correct me if I am wrong, transfer issue or Laser issue.
Thanks!!

Well..ROS replacement can b PIA.. can you rob an ITB to test?

Sent from my SM-G960U using Tapatalk

[Lance15]

Re: Lexmarl C748DE No Red at all

Correct me if I'm wrong, but, I think typically with these block type laser/scanners, there are two physical lasers that do two colors each. Say, BLACK & CYAN and MAGENTA & YELLOW. If you've got yellow, you'll have magenta too.

[Phil B.]

Re: Lexmarl C748DE No Red at all

Correct me if I'm wrong, but, I think typically with these block type laser/scanners, there are two physical lasers that do two colors each. Say, BLACK & CYAN and MAGENTA & YELLOW. If you've got yellow, you'll have magenta too.

well hell... yes they would split two colors... digress

so Lance you have narrowed it down to ITB!