Xerox C75 Duplex problem

[makutzi]

We are now also the proud owners of a C75, might be old but she works like a charm! That is until a week ago it stopped duplexing - well when a sheet moves into the duplexing unit it seems the rollers only take it in an inch or so, error comes up (paper jam) and then the sheet slips off. I have already cleaned all the rolles twice and the paper path as wel as the sensors I can see. Also now when I switch on I can hear the motor in the fusing part quite loud for a second or two.

What could have caused this, what needs to be replaced? I am very ned to this machine and have also not seen any error codes regarding this issue...where are they hidden?

Any help is welcome

[Piper]

Open the Paper Path Module and check if the Duplex Belt is okay and moving smoothly. If its not moving smoothly,
clean all bearings on the belt path and on the duplex rollers. You will have to remove the Fuser, 2nd BTR and a few other parts to access all the duplex belt and duplex roller bearings. I had the same experience on a Xerox 770 Press.

[Flash]

Also take out the white plastic rollers in the duplex unit and clean the shaft and the inside of the rollers.

[makutzi]

Open the Paper Path Module and check if the Duplex Belt is okay and moving smoothly. If its not moving smoothly,
clean all bearings on the belt path and on the duplex rollers. You will have to remove the Fuser, 2nd BTR and a few other parts to access all the duplex belt and duplex roller bearings. I had the same experience on a Xerox 770 Press.

Hi, thanks for the tip, just got a service manual and checked out the procedure to remove the mentioned parts. Thanks again, will definately give it a go.

[makutzi]

Also take out the white plastic rollers in the duplex unit and clean the shaft and the inside of the rollers.

Hi, thanks for the hint. will do. Thanks for the tip.

[makutzi]

So, I opened up the tray, removed the parts to be removed to gain access and as it turned out the belt of duplexing thing had slipped off, which was causing the grinding noise. That fixed, tried to duplex, still no luck, the paper comes out of the fuser, passes the decurler then into the inverter, travels about on to two inches into the duplexer and then it stopps, kind of past the first two rollers in the duplexer.

When the unit was open I cleaned out all the rollers and whatever could be cleaned. The duplexing belt however does not move all that freely if i move it by hand (tray open), it does require a bit of force. in one direction (towards the end ((right side of machine))) it moves much easier. I noticed at the front where the rods connect to the motor there is a gear with a directional bearing in it (it slips to one direction and grips to the other) maybe this one is not too healthy, will see and replace it and test again - not many bearings here, only small ones and they all spinn freely.

[makutzi]

I also noticed in the error log the last error shown was 077-130 and 077-129 - not sure yet what they are but think they relate to the duplexer problem.

[positiveg]

Did you ever get this issue solved?
We are having the same issue

[InterfaceP]

I didn't see in the previous post that there was a audible grinding. This is typicality due to an excessive load on the gears, in which case you would need to remove all the rolls to clean and lubricate them. If there is no audible grinding I would suspect that the Duplex motor is bad. Take all the covers off the Drawer assembly and locate the Duplex belt. I cheat the door open, and gently press the belt as the paper passes to feel if it rotates at all.

[positiveg]

I didn't see in the previous post that there was a audible grinding. This is typicality due to an excessive load on the gears, in which case you would need to remove all the rolls to clean and lubricate them. If there is no audible grinding I would suspect that the Duplex motor is bad. Take all the covers off the Drawer assembly and locate the Duplex belt. I cheat the door open, and gently press the belt as the paper passes to feel if it rotates at all.

yeah true you should hear that grinding noise. Mine is so loud feels as if the gears would just break off

We've changed the motor, the belt, the gears and still same issue, so we've been left with ordering in a Duplex Upper Assembly unit. Really hope this fixes it.
Cause right now the machine is down.