KM Magicolor 4690MF misfeeds & fuser not rotating

[blackcat4866]

I walked in to a jammed machine. The paper had a good transferred image, just not fused, with the paper bunched up below the fuser. With the jam cleared I could hear the steady "... thump ... thump ... thump ..." of a drive gear missing a tooth.

With the covers off I can see the two stage gear in the drive pack jerk each time it thumps. I can also see the interlock lever twitch with each thump. I'm guessing it's a ratchet clutch of some kind that stalls the drive when the right side door is open. The fuser turns easily enough, so I'm not worried about re-breaking the same gears.

Here's the problem: I'll have to strip the machine to get to the main drive pack to do a proper diagnosis on the drive pack. And the main drive is buried. Can you help me identify the specific gears, so the job can be done in one dis-assembly/re-assembly? =^..^=

[JustManuals]

Cat.....would you like a free copy of the Parts & Service manual? Just email me.

Paul

[blackcat4866]

Actually this will be a good opportunity to test out my login.

As of this week we are a Konica Minolta dealership. Oh, if only I could have a few hundred more models to be responsible for.
If I can't figure it out, I'll get hold of you. =^..^=

[JustManuals]

Okie dokie.

[blackcat4866]

Success on the login and manuals.

From the illustrations it looks as though there's a greaseable spring-wrap clutch with a release lever to stop the drive when the door is open.
The parts are pretty self-explanatory. I expect to find a wrapped clutch spring.

Next challenge: to figure out how to order parts from KMBS. =^..^=

[mjunkaged]

I've already taken the training course, it's not real in-depth though. Pretty sure you already know how to read a manual!
If it IS the spring, wonder what caused the fuser to bind up? Monster paper jam?
BTW, rated life of fuser if only 120k so if it's near that I'd plan on replacing it soon, if not now. Also, if the machine is under warranty or not? Since you're now a dealer! Don't pay for crap you should be getting free! But you probably knew that.....look who I'm talkin' to!

[blackcat4866]

The machines got 27k, so it's just a baby.

It's got an unusual sort of heat belt. It's orange on the edges and black in the 8 1/2" center. I examined it closely to make sure it wasn't a fuser wrap, or toner buildup. By all appearances it is intended to be that way. There isn't any evidence of a major fuser jam, but I suspect that was the case. (No letter opener pierce holes in the belt.)

I'm thankful that the drive wasn't overly complicated. One peek at the diagram explained it all. =^..^=

[blackcat4866]

Well, that task lived up to my expectations. 4+ hours of pure pleasure.

11546

I still don't have a good guess what made the clutch wrap, but wrap it did. It's not a wimpy spring either. What made it worse was the crappy fiber C-clips all the manufacturers are starting to use. When the spring wrapped twice, it spread the clutch 1.5mm pinching the fiber C-clip inside the bore of the outer hub. If there was a way to get to that clip, I couldn't think of it. It took ~45min to break the clutch into small enough bits that it came off, without damaging the shaft. In retrospect, I probably should have started nipping at the area of the C-clip with the big side cutters until the clip became visible. I installed a metal E-clip, which may very well prevent this, but it's hardly worth the effort as a preventative measure. It takes over 2 hours just to see the clip.

I'll detail the places that I screwed up, so maybe the next guy will get there quicker:

1) There's no sense in trying to insinuate yourself in there without removing a lot of stuff. The scanner has to go, the upper ductwork and FM1, three boards, inner and outer half of the board cage, handfulls of wiring harness,... it's all got to come off.
2) I think the first place I got stuck was the inner portion of the board cage. There was a screw remaining where I couldn't see it. That screw turned out to be behind the center divider plate. I was trying to remove the cage as an assembly, but that's not how it comes out. It disassembles a several separate pieces. The only part I could leave inside the cage was the engine PWB.
3) The pickup drive assembly has two gears on the opposite side of the frame that must be released before the assembly will come out.
4) The main drive pack is held in by 7 screws. The hidden screw is behind the top center motor in a deep dark recess. Again I was trying to keep the pack as whole as possible.
5) Once I'd gotten the uncooperative clutch replaced and that part of the clutch pack re-assembled, I noticed that the shafts did not set in there squarely. That's because there is a small flat on one side which must be aligned with a mating dimple on the metal frame.
6) When reinstalling the clutch pack, the gray harness around the exit side of the pack kept getting tangled in between the frames, threatening a pinched wire. Much fiddling to keep the wire clear.
7) There are several two pin clutch connectors in the viscinity of the top of the clutch pack it's very easy to swap connectors here. Color codes don't match. All the connectors are the same type and color.
8) There are three fans with three pin connectors at the engine PWB, two of which can be interchanged. The DC power supply fan gets installed last with the ductwork, and goes to PJ9. PJ29 remains empty. If you leave that fan unplugged it gives you an 004E error. Ask me how I know.

11547

If you'd like all the boring detail I can attach the Word doc. =^..^=

[Hansoon]

What a mess. Sometimes I believe that such machines are not being put together by man but somehow a biological structure growing in laboratories of a weird creepy scientist.

Hans