Drum or developer? Or both? TA250ci

[copier tech]

Re: Drum or developer? Or both? TA250ci

Enjoy!:

Great work hope I dont ever need to use it!

We usually replace the machine when issues like this needs replacing, old machine not worth the effort really.

[blackcat4866]

Re: Drum or developer? Or both? TA250ci

Often you can just print off the 4 pages of procedure and wave it around. "It's 3 hours if all goes well, without any complications ... and we both know how likely that will be. $375 best case scenario." You probably won't have to do the work. =^..^=

[kyove]

Re: Drum or developer? Or both? TA250ci

Thank you guys!!

A special thanks goes to BlackCat for the Guide.
It was just what I was looking for.
I've never disassembly a main drive on this model so having a guideline is very helpful.

Have a nice day,
Kyove

[jqueen]

Re: Drum or developer? Or both? TA250ci

Enjoy!:

I've seen this before numerous times with the 400ci....About 3 1/2 hour fix.... I didn't replaced the whole assy, I would find the missing pin and put the gear assy back together, making sure to put on some sticky lubricant on the pin cover on the connecting gear so that it does not come off again. Not a fun job in my opinion. No parts, just time...

[blackcat4866]

Re: Drum or developer? Or both? TA250ci

I believe the cause of the coupler coming off is the firmware that reverses the developing units, so that they run cleaner. The vibration causes the plastic ring to slip off, releasing the pin. The key to keeping the pin in is keeping the ring from slipping off. Some techs put a dot of superglue on the inside of the ring. I usually cut a 5mm wide strip of paper, fold it over to 2 thicknesses and slip it inside the ring. The additional tightness prevents it from happening again. =^..^=

[bush_tech]

Re: Drum or developer? Or both? TA250ci

I agree with all that. It's pretty common to have rear developing seals fail, and developer dump at the rear, destroying the gears.

I would add that in the more recent incarnations of the developing units and the matching firmware, Kyocera has added a "thumping" function at the end of each print cycle to shake down toner that tends to collect in the lower developer seal. The way it works is that the coupler on each developing unit is a ratchet, and at the end of each cycle the developing motors reverse for a few rotations to make the ratchet bump, and shake down the loose toner. Customers that remember the earlier developing units and/or earlier levels of firmware will notice the change in the sound. On a few occasions it was very difficult to convince the endusers that it is entirely intentional, and no ... nothing is broken.

More recent models have begun including a vibrator motor to each developing unit to serve the same purpose. It works just like the vibrate function on your smartphone: it has an offset cam that when spun up makes the developing unit vibrate briefly.

Other common noises might come from:
1) one or more seized drum cleaning units, often caused by an incompletely closed or broken latches for the vertical feed guide B1. The waste auger drive is driven through the Guide B1 feed shaft.
2) Transfer belt cleaning unit drive jumps. The rear transfer unit rail can wear out from repeated removal/installing of the transfer belt. It's a huge job to replace that rear rail (junk the machine if that's the case).
3) A seizing developing unit can cause a growling noise. You'll have to turn each developing unit by hand to find it.
4) Rubbing noise (4) times at power On, and when awakened from sleep mode: Friction where the cams drive the laser slit glass mechanism. To test press: System Menu, V to pg 2, Adjustment & Cleaning, Laser Scan Cleaning, Execute.
5) Squealing noise, intermittently. Possibly related to J91 & J95 jams in the DF-780 finisher: Lower gray rollers in the JS-720 job separator break loose from the shaft and slide to the outer edges of the cutout in the exit assembly. The sound results from rubbing on the sides of the slot, and creates gray rubber shavings. =^..^=

I remember reading a bulletin about those new devs, I'm pretty sure it suggested fitting the old dev back in if the client complains about the noise haha