C-350 black iu error

[newbie]

we have a c350 with a COF36 (black iu developer error) after about 30 copies after putting in a new chip. We put in a new iu and after about 100 copies it has the same error. any suggestions would be helpful and thanks for your time in advance.

[kmcopier]

check the connector if this is not bend too the back. also the atdc is on the unit so that can't be the case what about the quailty is this getting worse is there toner supplying check R35 on PWB MC

[newbie]

The cyan unit was also throwing an error code by the time I went back down. So I replaced the hopper unit assembly. There are two hopper motors one runs black and cyan and the other one runs the other two hoppers with one way bearings so the each motor turns both ways. Still didnt add toner so I manually added toner (very carefully) to get them toned back up to keep them running over the weekend. They weren"t still adding toner when i left friday but went back today (monday) with the board and they were working! So were putting our "parts" machine back together to see if it will work! Did notice both generic toner bottles were hard to turn at first. Thanks a whole lot for your help.

[Kmdurrin]

I have a C350 that is giving this same error code. Did manually adding the toner seem to fix the problem, or is there a different solution?

[Blenk]

i have had these problems before, with various c350 units, the first thing is, keep an eye on the generic toners, it seems that the sensors sometimes can not see through the clear window through the toner bottle, mainly the black, then the units run so low on toner you get your atdc sensor codes (cof's) also i have had a yellow and magenta not add toner and i found this to be 2 icp's on the controll board, cant remember exactly which ones, there is icp's on the front and the back of the controll board , be sure to check them all. i dont know exactly what caused my icp's to pop, but i noticed that on a board off a newer m/c i used for parts the value of the icp's were higher, and as soon as i put the new board on the m/c sorted its self out, and toned up to the correct levels... i was there for ages trying 2 figure out this one.... its probably all down to those lovely generic toners haha.

hope this helps

[Kmdurrin]

We are still having the same problem. The board checks out fine, the toner is OEM, and we have replaced the drive motor, but the machine keeps throwing a COF36 error code. Any other ideas? We're not too far away from trying to "fix" the machine with a hammer.

[minimerlin]

I would try to confirm if the toner is actually getting from the bottle to the image unit! You should be able to operate the machine with the bottle removed and watch the worms turning!

[labish]

The book said: C0F36 Abnormally low toner density
detected Black ATDC Sensor
• T/C 3 % or less is detected ten consecutive times in
the Developing Unit as validated through the toner
replenishing amount determination control so is clear enough is under 3% toner. Or the hopper is stuck or the dev. I had a few new IU install and after installing the unit the image start fading but the image adj was ok. So I took out whatever I replaced at that time give a good shake to IU and start again the image adj. If the machine was working ok before replacing the IU the hopper is ok. I did not replace an ATDC on this machine or at least not yet.