C2790 - 3551ci

[BillyCarpenter]

I have a 3551ci here in the shop and i pulled the transfer belt partially out to get the drum/dvs out. When I slid the belt back in I get a C2790 code. I checked the connector for any bent pins. All looks fine. Any ideas?

[copier tech]

Re: C2790 - 3551ci

I have a 3551ci here in the shop and i pulled the transfer belt partially out to get the drum/dvs out. When I slid the belt back in I get a C2790 code. I checked the connector for any bent pins. All looks fine. Any ideas?

Take the belt completely out, clean up any stray toner, refit. If that doesn't work update the firmware.

• Code: 2790
• Description:Intermediate transfer belt skew correction motor error
  When the transfer skew motor is driven, timeouts (300 ms) were detected twice in a row.
• Remedy:Transfer belt skew motor: 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. intermediate transfer belt unit and Engine PWB (YC3) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the intermediate transfer belt unit.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB

[BillyCarpenter]

Re: C2790 - 3551ci

Take the belt completely out, clean up any stray toner, refit. If that doesn't work update the firmware.

• Code: 2790
• Description:Intermediate transfer belt skew correction motor error
  When the transfer skew motor is driven, timeouts (300 ms) were detected twice in a row.
• Remedy:Transfer belt skew motor: 1. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. intermediate transfer belt unit and Engine PWB (YC3) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the intermediate transfer belt unit.
  Engine PWB: 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB

I've tired all of that and I tried another transfer belt. No luck on any of that. Everything turns freely...no binding. It's weird because all I did was pull the transfer belt out enough to get the drum/dv out.

[BillyCarpenter]

Re: C2790 - 3551ci

I'm really at a loss on this one. It was working fine before I released the transfer belt. I've eliminated the transfer belt, wiring connector and firmware. I'm about to replace the control PWB. Gotta eliminate what I can. Beats sitting here looking at the machine.

[blackcat4866]

Re: C2790 - 3551ci

On early production Saturn, there were issues with the skew adjuster mechanism (C2700). I seem to recall a bulletin in which we added some shims to the mechanism. The transfer belt had obviously walked 5mm off one side. I had replaced the first belt assy under warranty. I had saved the mechanism out of a transfer belt to fix the next one ... then never saw it again. Regardless, none of this is really applicable.

Just out of curiosity, take a look at the mounting screws for the AK730. On the early production AlphardI machines with the erector-set-AK730, the standard mounting screws for the front bracket were 20mm long. So what's the problem? The lower screw drove right into the transfer belt, causing it to track to the front and give C2770 errors. So when I saw those 20mm long mounting screws I would toss them in my tool bag, and use 12mm long screws. Several things have changed since then. Your AlphardII won't have the erector-set-AK730 ... but it may still have the 20mm long screws. I happened to discover this in class.
=^..^=

[BillyCarpenter]

Re: C2790 - 3551ci

On early production Saturn, there were issues with the skew adjuster mechanism (C2700). I seem to recall a bulletin in which we added some shims to the mechanism. The transfer belt had obviously walked 5mm off one side. I had replaced the first belt assy under warranty. I had saved the mechanism out of a transfer belt to fix the next one ... then never saw it again. Regardless, none of this is really applicable.

Just out of curiosity, take a look at the mounting screws for the AK730. On the early production AlphardI machines with the erector-set-AK730, the standard mounting screws for the front bracket were 20mm long. So what's the problem? The lower screw drove right into the transfer belt, causing it to track to the front and give C2770 errors. So when I saw those 20mm long mounting screws I would toss them in my tool bag, and use 12mm long screws. Several things have changed since then. Your AlphardII won't have the erector-set-AK730 ... but it may still have the 20mm long screws. I happened to discover this in class.
=^..^=

I replaced the Control PWB with no success. Didn't really think it was the problem but that's now eliminated. I didn't notice if before but I hear a clicking noise. Sounds like something is binding. Its not super loud but loud enough to let me know something is wrong. I have another 3551 and I don't hear the noise at all.

I removed the screws that you're talking about and I'm still getting the code. I need to find the assembly that driving the tranfer I belt, I suppose.

[copier tech]

Re: C2790 - 3551ci

I replaced the Control PWB with no success. Didn't really think it was the problem but that's now eliminated. I didn't notice if before but I hear a clicking noise. Sounds like something is binding. Its not super loud but loud enough to let me know something is wrong. I have another 3551 and I don't hear the noise at all.

I removed the screws that you're talking about and I'm still getting the code. I need to find the assembly that driving the tranfer I belt, I suppose.

You say you took out the drum/dev did you replace these any of these? if so may the dv is seized preventing the belt from driving.

[blackcat4866]

Re: C2790 - 3551ci

If you can, watch that the transfer belt is being driver consistently, no hesitating. Perhaps unrelated to the C2790, it was common on the Saturn to have the transfer belt guide bushings wobble.

The clicking you describe might be like the Saturn. On one machine I had the rear transfer rail wear. If I held the transfer belt in a specific position it would stop clicking. For your sake I hope that's not it. It was 5.5 hours to strip the front and rear of the rear frame to change out that rail.

Good luck. =^..^=

[BillyCarpenter]

Re: C2790 - 3551ci

You say you took out the drum/dev did you replace these any of these? if so may the dv is seized preventing the belt from driving.

The problem I was trying to correct was I had a very small spot that was faded when printing solid magenta. It was on the very edge of the paper. The customer would have probably never noticed it but it was bugging the hell out of me, so I replaced the magenta DR & DV but I had no problem with that, but it didn't solve the problem, so I pulled the cover off the magenta laser to clean the slit glass. When I put everything back together, that's when I got the code.

I figured from the beginning that this is a problem that I introduced to the machine because it was working fine before I touched it.


I'll go back and retrace my steps. Thanks.

[BillyCarpenter]

Re: C2790 - 3551ci

If you can, watch that the transfer belt is being driver consistently, no hesitating. Perhaps unrelated to the C2790, it was common on the Saturn to have the transfer belt guide bushings wobble.

The clicking you describe might be like the Saturn. On one machine I had the rear transfer rail wear. If I held the transfer belt is a specific position it would stop clicking. For your sake I hope that's not it. It was 5.5 hours to strip the front and rear of the rear frame to change out that rail.

Good luck. =^..^=

I'll try that, also. I'm assuming that I can cheat the door switch and watch the belt?

[blackcat4866]

Re: C2790 - 3551ci

On the Saturn I removed the side cover, opposite the door. I'm not sure how that would work on the AlphardII. =^..^=

[BillyCarpenter]

Re: C2790 - 3551ci

If nothing else, this is a good learning experience. I replaced all the drums and DVs just to make sure nothing is binding. That didn't help. I did learn that, unlike the 5551, there's only 2 motors for the drums/DV's. One for the black and the other drives all 3 colors. I also learned that there's a single motor that's responsible for turning the transfer belt - direct drive...no gear assembly.

I still hear the clicking noise and still getting the code. I took the covers off the rear and watched all the motors as it made the clicking noise. No visible motors were turning. The motor that drives the transfer belt isn't visible so I couldn't watch it but I can turn the drive gear freely when I pull the transfer belt.

Time to take a break for a few and I'll get back on it.

Thanks for the help, guys.

[BillyCarpenter]

Re: C2790 - 3551ci

On the Saturn I removed the side cover, opposite the door. I'm not sure how that would work on the AlphardII. =^..^=

I don't see a way to do this right off hand. It would be most helpful if I could watch the transfer belt. I'll see if I can figure something out.

[tsbservice]

Re: C2790 - 3551ci

From reading that error description I would think there is dedicated motor(transfer belt skew correction motor) that needs to be checked. Not the motor driving belt.
Please neglect my post if motor is the same.

[BillyCarpenter]

Re: C2790 - 3551ci

I have it narrowed to a couple of things.


There is no binding with the transfer belt itself.

There is no binding in the transfer drive section.


There is a clicking noise when the machine is booted and does its diagnostics and I get the C2790 code.

One of 2 things is happening. Either the drive motor for the transfer belt it going bad or the transfer belt guide is worn like blackcat said and the gears aren't engaging properly. But when I put the transfer belt in the gears look to be engaged perfectly, but who knows what's happening when the motor starts turning and I can't find a way to view the belt under normal operation.


The drive motor for the transfer belt is a bitch to take off so I'm gonna install another transfer but first but I think that's pissing in the wind. We shall see....