Sharp MX4501N POD2_N Ghost Jamming and strage noise

[repn1999]

I have a Sharp MX4501N out in the field that just recieved some maintenance. The machine was purchased with L4-10 on it. After a good cleaning and replacing all feed and seperation rollers, doing all the maintenance(drums, devs, fuser rollers and web) the machine was sold. Customer ran about 75K black and 28K color and then the machine started jamming. We replaced the entire delivery unit and right door units. Copier was running ok for about 2 weeks but still jamming occasionally. POD_2 was the jam code displayed. But I cannot get it to jam while I am there on site. This customer runs almost all duplex copies and tends to do larger batches of copies at one time....screen play scripts and part lines for plays. Typical job may be 60 sets of 40 pages double sided. Machine then pops for transfer belt maintenance. We install both transfer kits. Calibrate and everything looks good. Customer calls back next day and says its jamming agian. This time I go out there and get it to jam. It runs about 100 copies before it jams but it does. When the jam happens the machine makes a grinding noise, similar to the sound of a belt slipping but not quite that of a gear stripping. Paper is wrinkled above fuser. You un jam it and it runs some more, but the number of copies between jams decreases. I have tried swapping exit units and fusers with no luck. I have changed out an MXRBX1 unit with no change. Anyone have any ideas? The imager has about 600k total on it. The customer runs good GP multipurpose paper that we recommend for all of ouor MX customers and have no problems. Please help. Im no a cheapo, I just need to get it fixed however I gotta do it.

[OMD-227]

Starting to see this exact situation alot more lately, as these original MX's get abit older.

I know you said that you have changed the entire side door (along with alot of other items), but this exact symptom of POD2 jams, with a noticable grinding noise as it comes to a stop, is usually the Reverse PG having a slight warp in the middle at the position the POD1 arm. The original type Reverse PG warps/bends outwards (heat damage - high volume machine), causing the POD1 arm to not fully return correctly. The POD1 sensor is still down from the trail edge of the last sheet as the lead edge of the next sheet comes along, always causing POD2_N and the very noticable & concerning grinding noise as it stops (which is the fuser drive motor disengaging while fuser still turning).

The Reverse PG unit has been modified a few times now, and includes 4 pawls attached to it which not only help guide the paper through, but also stop any hard toner buildup on the guide & gate. The Reverse PG unit has a moulding in the section that the POD1 arm sits inside when the door is closed that prevents the POD1 arm from becoming stuck or not returning fully.

Attached pictures of new parts (actually been out for quite a while, but definitely fixes alot of POD1 & POD2 jams on the C-Jupiter).

Also, just check the delivery unit ribs have no hard toner buildup on them. You can either shine a torch in there, or remove the delivery unit & take the top section off to have a good look.
I've also seen a few moulding problems on the POD1 arm on the fuser. If you have a look at some earlier version fuser units, the POD1 arm is about 2-3mm shorter than what it is now. This extra POD1 arm length obviously would make the POD1 arm be down just a split second longer than normal as the arm is longer. I've had to trim the excess off some POD1 arms as the arm is not returning quick enough. On that note, also make sure there is enough tension on the POD1 spring inside the fuser. Take the web unit off and clean the joints the arm touches and add tension to the spring if needed.

You seem to have done everything else OK, infact, probably going too far, but that a good thing.

[repn1999]

I replaced the entire fusing unit, since I did not have ready access to a spare Reverse PG and didnt want to just order one part from sharp. Figured the thing could use a new one anyhow with it being a high volume machine and all. Anyhow, the machine has been working for 3 weeks without jamming at all, and then bam, right back to POD2 jamming every copy. Any more ideas? New fuser has approx. 2200 copies on it and its of the newest rev.

[OMD-227]

You must do the mod for the reverse PG. The POD1 sensor arm sits in the small cut-out in the middle of the reverse PG. When the reverse PG has a small warp in the middle (heat damage), the part must be replaced with the new version.

As both POD1 & POD2 sensors are located on the delivery unit, make sure both sensor arms move freely and actuate the sensors fully & freely. Also reseat the cables going to the delivery unit just as a precaution.

I still think this has alot to do with the reverse PG. The more I read your first post, the more I see the same symptoms I see quite often here.

[repn1999]

I replaced the enitre reverse PG unit and the fusing unit with new rev. ones from Sharp. I assume the mod you are referring to is the one pictured above. I will print em out and go verify that they are done. Also I went out to the customers office today myself, and the jam codes are POD1_N and POD2_N. about half and half mix of each code.

[OMD-227]

POD1_N is different altogether. Thats paper not even passing through the fuser.

How do the upper & lower pawls look? Are you sure they are using good quality, low moisture paper? Now I'm starting to think this is something completely different.

Adjust the fuser entry plate with the 2 screws. Adj default fuser temp settings by changing sim 55-01 switch2, bit 1 (change 00000000 to 10000000). If that change has been made previously, reset to default 00000000.

[repn1999]

They are using Georgia pacific prem. Multipurpose paper so yea the paper is ok. We actually recommend using it in all of our color copiers. That or the hammermill paper that sharp recommends for calibration is what we use. Fuser temps were increased 10 degrees to combat streaking on photo paper but I'll reset it first thing tomorrow to rule that out.

[repn1999]

And like I said the entire fuser was replaced 2200 copies ago with a new rev one.

[OMD-227]

Have you adjusted the RBX1 drawer reversing gate solenoid position out to its furthest point to increase the opening margin? I know you swapped it out with another one, but the solenoid position is adjustable, and i've seen all sorts of positions in place. Sometimes opening up the gap is needed for the lead edge to clear through if there is any paper curl.

I know this might sound lame, but have you checked the first sensor in the RBX1 drawer has good spring return & hasn't got a small paper cut in it. I've had a few that the lead edge got caught on which slowed the paper transport speed down, causing the following sheet to stick at the fuser.

[repn1999]

This may surprise you but yes I know about the rbx mod and it's in the furthest left position if u are facing the machine. We actually note the service card if any mods are made and what the bulletin number is for future reference. ALWAYS. I'll look at the flag tomorrow to be sure it's clear of nicks cracks etc. Btw thanks for your help with everything.