Ricoh MPC4503 - Duplex Jam at Fuser / Paper Exit Unit

[Peter Zeravla]

Hello everyone,

I'm using a Ricoh MPC4503 and I'm experiencing a paper jam issue that only happens when printing double-sided (duplex). The paper gets stuck in the fuser area, right before fully exiting the Paper Exit Unit. I’ve observed that during duplex printing, the machine normally partially ejects the sheet through the Paper Exit Unit before pulling it back into the duplex unit to print the second side. However, in my case, the sheet never fully exits—it gets stuck right at the exit, and the rest of the paper crumples inside the fuser.

Here’s what I’ve tried so far:

• Replaced the fuser with a working one
• Swapped the Paper Exit Unit with one from another identical machine
• Blew compressed air to clear any debris
• Same issue every time

Because the paper never reaches the duplex unit, I don't think the duplex unit itself is the problem.

I’d like to test the motors involved in duplexing and the Paper Exit Unit. I tried accessing SP mode 5804 to manually operate the motors. I was able to activate the fuser fan motor with the right-side door (duplex area) open, but when I try to move the fuser or duplex motors, nothing happens.

A few questions:

1. Can the motors be tested with the doors open, or do they need to be closed for operation?
2. Which motors and sensors should I focus on, based on the symptoms?
3. Any advice on how to troubleshoot this further using SP mode?

Unfortunately, I don’t have a photo of the jammed paper right now, but I will upload one as soon as I can.

Thanks in advance for your help!

[MIGUELMARCHENA]

There's a guide in the duplex that's deformed or broken, check it... but I hope you put the jam code because it helps to know more or less where the problem is.

[Popolopo]

Try change IOB transport. The one behind power supply.

[slimslob]

It would be nice if they had provided the numeric jam code, Jxxx where xxx is a three digit number. That code tells what sensor detected the jam and whether it was a lead edge or trail edge

[luca72]

Hello everyone,

I'm using a Ricoh MPC4503 and I'm experiencing a paper jam issue that only happens when printing double-sided (duplex). The paper gets stuck in the fuser area, right before fully exiting the Paper Exit Unit. I’ve observed that during duplex printing, the machine normally partially ejects the sheet through the Paper Exit Unit before pulling it back into the duplex unit to print the second side. However, in my case, the sheet never fully exits—it gets stuck right at the exit, and the rest of the paper crumples inside the fuser.

Here’s what I’ve tried so far:

• Replaced the fuser with a working one
• Swapped the Paper Exit Unit with one from another identical machine
• Blew compressed air to clear any debris
• Same issue every time

Because the paper never reaches the duplex unit, I don't think the duplex unit itself is the problem.

I’d like to test the motors involved in duplexing and the Paper Exit Unit. I tried accessing SP mode 5804 to manually operate the motors. I was able to activate the fuser fan motor with the right-side door (duplex area) open, but when I try to move the fuser or duplex motors, nothing happens.

A few questions:

1. Can the motors be tested with the doors open, or do they need to be closed for operation?
2. Which motors and sensors should I focus on, based on the symptoms?
3. Any advice on how to troubleshoot this further using SP mode?

Unfortunately, I don’t have a photo of the jammed paper right now, but I will upload one as soon as I can.

Thanks in advance for your help!

Since I have not provided the jam code, I can only tell you that generally in that type of paper output unit of that series, it is the return spring of the gate solenoid that lets go, try cutting it by one turn, or putting in a slightly harder calibrated one, it is very easy even when trying another unit to encounter the same defect.

[Peter Zeravla]

It would be nice if they had provided the numeric jam code, Jxxx where xxx is a three digit number. That code tells what sensor detected the jam and whether it was a lead edge or trail edge

You're right. The error code is J024. I’ll upload some pictures showing the issue. In the one ending in _02, you can’t actually see the paper, but it’s there—just about to come out. That’s the key detail: the sheet never comes out at all, even though it should briefly exit before being pulled back in to print the second side.

The jam happens with the very first page trying to exit during a duplex job.

Thanks again for your help!

[Peter Zeravla]

There's a guide in the duplex that's deformed or broken, check it... but I hope you put the jam code because it helps to know more or less where the problem is.

Thanks for your reply!
I actually tried replacing the Paper Exit Unit with one from another identical machine, but unfortunately the problem remains the same.

So I think we can rule out the exit unit itself.

Appreciate the suggestion though—any other ideas are very welcome.

[Peter Zeravla]

Since I have not provided the jam code, I can only tell you that generally in that type of paper output unit of that series, it is the return spring of the gate solenoid that lets go, try cutting it by one turn, or putting in a slightly harder calibrated one, it is very easy even when trying another unit to encounter the same defect.

Thanks for the suggestion!

I actually tried swapping the Paper Exit Unit with one from another identical machine, and the issue remains exactly the same. So I don’t think the problem is in the solenoid itself (since it comes built into the Paper Exit Unit and I’ve tried a different one).

But now I’m wondering—what if the problem is that the machine isn’t sending the signal to activate the solenoid? That could explain why the guide doesn’t switch position to allow the paper to exit before duplexing.

Do you know if it's possible to test this kind of solenoid or switching mechanism using SP mode #5804? I’ve tried to use it, but I’m not sure which motor or actuator to trigger, and nothing seems to move when I try.

Any advice on how to test that from the service mode would be greatly appreciated.

[MIGUELMARCHENA]

Look, this problem occurred to me when the part I see in the photo was broken, improperly seated, or warped from heat.
This prevents the solenoid from working properly.
The first time I tried placing a piece of paper on the sides. First, I tried one and then the other, and it worked... It was a machine that worked all day.
Be careful, that part is very delicate.

[copyboy99]

exit unit

[Peter Zeravla]

exit unit

I don’t think that’s the issue in my case, as you can see in the photo I’ve attached of one of the Exit Units I’ve already tested. The problem persists even after swapping it, so it seems to be coming from somewhere else.

Thanks anyway for the input!

[luca72]

Thanks for the suggestion!

I actually tried swapping the Paper Exit Unit with one from another identical machine, and the issue remains exactly the same. So I don’t think the problem is in the solenoid itself (since it comes built into the Paper Exit Unit and I’ve tried a different one).

But now I’m wondering—what if the problem is that the machine isn’t sending the signal to activate the solenoid? That could explain why the guide doesn’t switch position to allow the paper to exit before duplexing.

Do you know if it's possible to test this kind of solenoid or switching mechanism using SP mode #5804? I’ve tried to use it, but I’m not sure which motor or actuator to trigger, and nothing seems to move when I try.

Any advice on how to test that from the service mode would be greatly appreciated.

I meant the spring to shorten because it becomes loose, not the solenoid, nothing, but I don't think that's the problem, because from code j027
for 5-804, I don't remember the exact sp, but you should find it quite easily, I think it's called "inversion gate" or "exit gate" or something like that
anyway if in doubt, you can still order a new one, it won't do any harm, it costs about 5 euros, I'll give you the code
D1494434 TENSION SPRING:LEVER:GATE PAWL 5,15 €

[slimslob]

You're right. The error code is J024. I’ll upload some pictures showing the issue. In the one ending in _02, you can’t actually see the paper, but it’s there—just about to come out. That’s the key detail: the sheet never comes out at all, even though it should briefly exit before being pulled back in to print the second side.

The jam happens with the very first page trying to exit during a duplex job.

Thanks again for your help!

J024 is a jam where the lead edge is not detected by the fusing exit sensor. It could be the sensor itself having failed from over heating or it is just dirty. If so then there could also be a problem with the fusing exit fan. The fusing motor stops faster than the paper transport motor causing the accordion fold at the trail edge.

If the sensor is mounted on the duplex door it could also be a damaged cable going to the sensor.

[luca72]

I found this:

[Peter Zeravla]

J024 is a jam where the lead edge is not detected by the fusing exit sensor. It could be the sensor itself having failed from over heating or it is just dirty. If so then there could also be a problem with the fusing exit fan. The fusing motor stops faster than the paper transport motor causing the accordion fold at the trail edge.

If the sensor is mounted on the duplex door it could also be a damaged cable going to the sensor.

Thanks a lot for the detailed explanation — it makes a lot of sense.

Just to clarify, I’ve already tested the machine with a different fuser, a different Paper Exit Unit, and also swapped the guide in the duplex. The issue still happens.

I also blew air on the Fusing Exit Sensor, but that didn’t help. So now I’ll try replacing the sensor entirely, since it really does sound like it could be the source of the problem.

The Fusing Exit Fan seems to be working fine — I was able to activate it through SP mode 5804-110.

Your point about the fusing motor stopping faster than the paper transport motor really explains the accordion fold I see at the trailing edge. That matches what’s happening in my case.

One thing I didn’t fully understand: when you say “if the sensor is mounted on the duplex door,” could you explain a bit more? In my case, the paper never reaches the duplex unit — it jams just before exiting the Paper Exit Unit.

I’ve also attached a photo where I’ve marked the area where I believe the Fusing Exit Sensor is located. Please let me know if I’ve identified it correctly, or if the actual sensor is somewhere else.

Thanks again for all your help!