c410dn Cyan Toner Pump Won't Turn

**RLGeek** · 09-18-2019

Hi guys,

I've got four c410 and c420dn printers. I have one in my office that works great. I have three in the shop that I'm trying to "marry" and fix at least one or two.

One is pretty new and seems to work fine except - I can't get the Cyan Toner Pump to turn/work!!

So far, I've tried...

- Change the pump, nada.
- Change the wire harness, nada.
- Swapped Cyan and Yellow connections, the cyan pump then works. (Ruled out a dead motor, jammed gears, etc.)
- Tried to Force Cyan to run in service, nada.
- Even replaced the cyan toner sensor next to the pump, nada.

So I'm stumped and now more determined than ever to beat this thing! LOL It prints and it there are no errors but the Cyan pump simply won't turn and it's not the pump mechanism itself.

Any ideas?? (Other than standing over it and dribbling cyan toner in manually. Ha! (Yuck!)

**totoro** · 09-19-2019

If you've swapped the connectors and then it works ; I would go for the board that's sending the on signal.

**RLGeek** · 09-19-2019

Replying to my own thread... (SOLVED)

I replaced the large circuit board along the bottom that the toner pumps (and just about everything else) plugs in to and that fixed the problem.

SO.... there is likely a component on that board that could likely be diagnosed and replaced but one of these printers was destined to be the "parts bin" so it all worked out.

AND - All of you veteran printer techs should love this... "Rookie Mistake!" - I also replaced the top toner tray plate because some idiot (def not me) broke three of the four plastic index tabs that help hold the toner bottles in place on the business end. When I replaced it, the foam toner "gaskets" between the toner pump assemblies and the plate were stuck to the bottom of the broken plate. So I dumped a lot of cyan toner everywhere when I tested that pump after the replacement. I had to take it all apart again and move the gaskets over. Fortunately, since I was only testing the cyan, I only made a huge cyan toner mess, not a full CYMK mess! (Thank God for small favors I guess.)