C35 Misfeed, Jams on duplex

**giddyupngo** · 04-19-2016

Hi,
Still trying to fix a C35 that jams on duplex right when the paper reverses to get pulled back into the machine. Here is the story starting with most recent.

Customer called back in April, Customer said the duplex function only lasted one day when I returned it last time, but did not call in this problem. Replaced the Duplex Reverse Drive Assembly A121R70300, which did not solve problem. Replaced Clutch #1 (Media Feed Clutch) thinking it was involved in timing, because the C35 measures the length of the paper by timing sensors that are flagged as paper moves. This made it work great. I ran over 300 duplex copies of letter size paper from multiple trays. I delivered the machine back to the customer, ran a single duplex legal sheet, and it jammed. Then I tried letter size on duplex and that started jamming again. This machine is not under warranty, and all the other copytechnet posts about this duplex problem had Konica Minolta give them a new machine. I think it has to do with timing, since running plain paper on thick setting seems to work better, and physically trimming the paper seems to stop the jamming too. Page 106 of the Theory manual talks about this internal measurement of paper, involving PS3 (Media Feed Sensor) PS5 (Registration Sensor) and CL3 (Registration Roller Clutch). These three things I could possibly replace. Another option is replacing Clutch 13 (duplex Conveyance/transport roller clutch) and the PRCB as a set per this bulletin (Display) I do know that ICP2 on the PRCB is not blown. I did replace Clutch #13 because I replaced the Duplex Reverse Drive Assy (A121R70300) which includes that clutch. The rest of the story is below, please let me know if anyone has any other suggestions.

2/23/2016 4:57:51 PM
Took apart duplex reverse section. Noticed that the Paper full sensor was disconnected, connected it, cleaned both exit rollers/tires, took apart the new Clutch 11 and 12, and cleaned plates with IPA. Now printed 100 duplex copies OK. I think it was cleaning the clutches that fixed it.

It seems like duplex section is losing power after few prints tray to replace the harness for the vertical conveyance section.

As far as machine prints simplex fine please attach management list to the request.
2/23/2016 12:12:43 PM ;
Tried a known good used PRCB, no change, jammed on first duplex copy.

2/23/2016 11:37:17 AM ;
To follow up on Thick 2 setting for tray 2, Started 100 copies duplex, 48 printed without jamming, then the copier stopped and did not finish the job. Maybe stuck during calibration? Will try a different PRCB now.

Actions taken by caller:
1. Replaced the DUP assy> same issue
2. Went into sensor test in service mode>>checked and all working.
3. Tray 2 paper changed to thick 2> runs 20-30 pages.

Actions taken while on call:

Recommendation:
1. Try another PRCB> test
2. Contact your DSM.

2/23/2016 11:04:17 AM
Replaced A0VDR71722 DUP Transport Assy (new), no change, still jamming on nearly every duplex copy. 10 sheets singe sided OK.

Actions taken by caller:
1. Fuser exit jam
2. CL13: Duplex conveyance roller clutch

Actions taken while on call:
1. Trail edge 3/4 " past the flag for the duplex
2. We checked voltage at PRCB connector PJ16
pin 14- 24vDC= 23.9v (duplex conveyance roller clutch)

Recommendation:
1. A0VDR71722 DUP Transport Assy

Actions taken by caller:
1. Fuser exit jam
2. CL13: Duplex conveyance roller clutch

Actions taken while on call:
1. Trail edge 3/4 " past the flag for the duplex

Knowledge Article KBA01100418 has been related to your request REQ000000152238

Click the URL below to view the details of the Knowledge Article: Display
(You must be signed-on to www.mykonicaMinolta.com to access the Knowledge Article)
2/23/2016 10:17:08 AM
There is no part number for CL13 in the parts manual, do you know what it is? I took it apart and cleaned the two plates with IPA. There was no improvement.
2/23/2016 9:32:19 AM
Thank you for the update
Have you replaced CL13?
2/23/2016 8:28:17 AM
Checked ICP2 for continuity, is not blown.
2/22/2016 10:21:51 PM
I checked the PJ6 and PJ16 connections. Tried to do the service mode component check to check the clutches by listening for clicks. Only a few click, most don't. Replaced Clutch 11 and 12 with new ones. Replaced M2 with a used one. The registration sensor flag was knocked out of its pivots, corrected that. Replaced fuser. After turning machine on after replacing Clutches 11 and 12, 70 duplex copies went OK, then started jamming on duplex every time. Single sided seems to work most of the time now. Now on duplex the paper is ALMOST completely ejected into the output tray, and at this moment when it should reverse, it just stops. Next I will replace Clutch 13 and check ICP2 on the PRCB, as there was a bulletin that said to replace those two things together.

Actions taken by caller:
Misfeeding out of all trays
Stops half way out of machine
Checked Sensors
Cleaned Roller
Replaced Fuser

Recommendation:
Check Connection at PRCB PJ6
Check M2 for proper drive
Cl 13 Connectors CN-20 and PJ 16 at prcb
CL 13 operation
M2 operation check
Replace CL13

**JR2ALTA** · 04-19-2016

It's too difficult to read your entire, long post. But I will say I had a similar problem and it had to do with how to cover/door was attached. The screws fit in and it appeared normal, but the door wasn't "snapped" truly into place, there were tabs or something that caused the idle rollers to distance enough from the drive rollers to cause the duplex jams.

**TheBlueOrleans** · 04-20-2016

I actually have an SSD ticket open for this very issue.
Runaround was: Replace DUP/Reverse Drive assy (didn't fix), both clutches in the DUP/Reverse Drive assy (didn't fix), PRCB (didn't fix), and the fun one: Reverse clutch and PRCB together at the same time.
ICPs on PRCB were all intact per continuity check, thus negating the necessity of replacing yet another known good PRCB and showing that the clutch wasn't killed by a bad PRCB. Same exact issue as you're describing, stops immediately upon reversing.

Latest and greatest fix for this particular issue is:

Replace the right side door assembly.

Part number: A121R70244. HIGHLY recommend ordering new instead of using a part stripped from another machine. Duplex clutch in side door has been upgraded, possibly for this very reason.

If that doesn't fix my machine, (first, I'm going to be very upset, as will the customer) I'll be headed towards replacing the whole blasted thing with a C3350.

C35s and I have what I like to call a "hate/hate relationship". But I'm not here to complain.

**giddyupngo** · 04-20-2016

Thanks JR2ALTA, I will check the cover on the door for that tab issue. And TheBlueOrleans, glad to hear I'm not alone. Please let me know if the right side door fixes this issue.
Thanks!

**TheBlueOrleans** · 04-22-2016

Replaced right side door. After rebuilding the machine and responding to comments about how "I really took that thing apart" I tested the duplex function and confirmed normal operation.
I do not know what in the side door caused the problem, but it's running duplex now.

**korthr5** · 04-26-2016

Hello

Maybe that ?
TNGB1300006EN00_C35 Duplex Jamming.pdf :: Free File Hosting - File Dropper: File Host for Mp3, Videos, Music, Documents.

**giddyupngo** · 05-06-2016

Tried known working PRCB, and known good M2, no improvement.
Today I replaced the Vertical Transport Assembly A121R70244 (Right Door). No change, still jamming on duplex. In fact the first letter duplex copy jammed in the same place.

At this point I have no idea what else to try. Konica Minolta does not sell a Main Drive assy for this. Hopefully the parties involved will agree on replacing the whole thing.

**habik** · 05-07-2016

On the bottom of the registration assembly (rear side), the duplex unit doesn't attach properly if the lip / hook has been snapped on the registration side and the eye on the duplex has nowhere to hook on to. Put folded paper on the door side where the duplex rear hinge (hook/eye) is resting (see picture). There was no hook on the manual, that I could take a screenshot. When it improves, then you may have to screw the hook in to the reg. assy.
C35 Duplex unit.jpg

**giddyupngo** · 05-12-2016

Thanks Habik, I did have one like that, but not this one.

**giddyupngo** · 05-12-2016

Problem Fixed, Thank the Lord!!!!!

I was replacing Clutch #8, and saw a gear clutch that was disengaged in the main drive. I am attaching a PDF I put together with pictures and instructions. If this is your issue, it is easy to test for it. This may be common, as a parts machine had the same issue. Besides making sure the gear is engaged, make sure that the compression spring is biting/gripping the plastic hub. Unfortunately you can't buy the main drive, so unless Konica Minolta makes this available or cross references it, this gear and spring can't be bought. After replacing the spring with an alternate one that grips better from a parts machine, I was able to run 100 duplex letter and 100 duplex legal.

If this solves your problem, please send me two weeks of your pay (the time I saved you) or the cost of a replacement C3850 you were going to get, whichever is higher. (Just kidding)