Could not even get toner motor to move in Sim 135. I have installed a repaired engine pcb and a new toner motor as well as a new developer unit. I can now get the toner motor to turn in Sim 135 but the machine still won't add toner. I pinned out the wire harness for the dev unit and I even tried a Sim 20 reset in desperation with no luck. Also flashed firmware early on in the process. I'm thinking that maybe the repaired board may be bad and am thinking about buying a new board. I am pretty sure the main board is not involved in the process. Appreciate hearing from anyone who has seen anything similar. Thanks.

I encountered this on a KM-2550 as well. The machine ran perfectly fine and showed no errors, despite the toner motor not running. The machine also never indicated an out of toner state. The fix turned out to be the engine PCB. We used a *new* PCB rather than a repaired one, so yes, the repaired board might be the issue still.

We had this very problem some months ago on a 2550 here. I did not do the repair, but I want to say that the fix was a new drum unit or a piece on the drum unit. I will check with the tech who did it and post it later. I remember that the machine was in our shop for a week while different things were tried.

Sadly I've been burned by repaired boards enough times I no longer use or trust them.

Had this on 3 units so far. NEW pcb should fix. Also check operation guide for shake toner bottle instuctions, if toner is packed to one end, it wont add, even if sim135 is used. Also ensure steps 16 and 17 have been carried out of page 105 of
Basic operation guide

I changed the engine with a new one as well as the main board from the brand new machine we got for the customer that had the original machine, without success. Haven't had much time to deal with the problem machine except when trying to use the developer from it. The machine I tried it on would not add toner. Supposed to be getting some "help" soon so I am planning on exploring that possibility.

We had one that had a void streak, which corresponded to starvation on the mag roll. No add toner message. What was left in the DV unit (not much) looked a little caked. The DV was replaced OK and then the symptom re-occurred after a couple of weeks. I stirred up the remaining toner in the DV unit and cleaned the face of the toner sensor. Shook up the toner cartridge as well as the one in the box on the floor next to the machine. Ran U130 yet again. Key operator trained about agitaing the toner. We've been good now for 7-8 months. I feel there may have been a bad batch of toner...not sure though.

This message has been edited. Last edited by: DaveH,

I just tracked down the tech that repaired the machine I was thinking of. It was a KM-2550 that simply would not add in toner at a fast enough rate to keep up with normal copying. He could run sim to forcibly add toner and have it be OK for a short run, then it would fall behind again.

Replacing the drum kit (whole drum/cleaning/MC assembly) was the final fix. All the other stuff listed in your problem was tried first in the machine also.

Thanks for that info Chris

I had 2 machines that would not add toner and copies would wash out. But it won`t say add toner. Turned out to be a bad toner cartridge on both.The gear won`t turn on the coupling correctly.That was a year ago.