Persistent Fuser Jams in the xerox 5090

and Docutech family

 

     

 

 By Raymond Cote

 

 

One of the most disturbing problems I have ever come across is persistent fuser jams that seem to defy logic, in spite of all the parts you change.  I recently responded to a service call on a Xerox 5390 copier for 10-102’s.  The most common cause is a worn idler gear in the fuser drive assembly. Sounds simple to correct doesn’t it? Just replace the Fuser Idler gear ((7K1700) and the fuser drive gear (7K120). Or use the fuser repair kit number 600K17920.  After deciding to replace the gears, I performed a simple fuser trim on the metering assembly, checked copy quality and ran about 250 copies.

The following day I received a recall for 10-102 fuser wraps. When I arrived at the account one of the first things I checked was the MIM compressor and made sure the air pressure was about 20 pounds. The Fuser air knife was a little contaminated from the fuser agent but Fuser Cleaning Solvent Pads (43P89) managed to clean it up quite well. I then used a common staple to make sure all the air holes in the air knife were open.  I replaced the Air Knife Solenoid (121K5500) in DC-330 after exercising it and noticing it did not give a sharp blast of air when commanded to.  Then, so as not to get egg on my face for a third service call (for the same problem), I decided to check the Air Knife Manifold and Fuser Roll Clearance (ADJ 10.2), and Air Knife Manifold Pressure regulator (ADJ 10.13). The Fuser Heat Roller (22K41520) and the Pressure Roller (22K6941) appeared to be in decent condition, but as a final check I ran almost 1000 sheets of paper through the 5390 without any fuser wraps.  Case closed I thought.

Yep, you guessed it. Three days later the customer called in for the same problem, 10-102 fuser wraps.  Getting a little desperate I opened my book of tricks to see what, if any thing, I had missed. When the fuser wrap occurred, I was able to peel off the copy from the Fuser Heat roller and compare it to the original. For the most part the copy was registered perfectly. Therefore, it was (probably) not a timing issue.  The Fuser Heat roller seemed to have a fairly even coat of fuser agent on it and the metering assembly appeared to be o.k. as well.  The HSFI counter for Prefuser Belts (600K8320) was well below the recommended replacement parameter. However, when the Prefuser Transport (22K14501) was removed, some of the vacuum holes were slightly blocked. Maybe not enough to stop the transportation of paper to the Fuser module, but maybe enough to slow the paper up a little and make it late for the Puffer solenoid. With a cleaned Prefuser transport and new Prefuser Belts I was ready to try it again. This time I could not get 100 copies through the fuser assembly without a fuser wrap. It’s times like this that you actually start to think that your entire career is being flushed down the toilet because you can’t resolve a stupid fuser wrap problem.

It became apparent that the Air Knife Solenoid was working properly and was delivering a crisp blast of air to the Air Knife assembly, while the copier was in diagnostics, and the fuser drawer was open.  I was not sure if that was happening when the Fuser Drawer was in the closed position while the copier was printing I began to think. The Air Tube (52E1300) from the Compressor to the Air Knife Solenoid could be cracked or in some way damaged.  So, I removed it from the Harness Assembly and examined it.  Afterward, I installed a new hose and the copier was returned to service.  Case closed?  Not yet. The tool bag wasn’t packed before the customer complained about repeated 10-102 fuser wraps.  I was starting to run out of things to do and my documentation suggested that I take two weeks off and go on vacation.

Something was (probably) slowing the copy up while it was in motion to the fuser assembly, but the question was what was it?  Instinct suggested that I start at the paper tray and work towards the Fuser Module. I started off with Paper Plate Parallelism / Stack Height (ADJ 8.2) to make sure the problem was not from the tray three areas.  It may seem like a waste of time to do this but it was one adjustment that had to be eliminated.  The tray had to be adjusted and that seemed to help the problem a little.  Actually everything we did seemed to help a little, but nothing we did actually resolved the fuser wraps. It’s times like this when you resolve problems that make you feel good about yourself.  I was ready to push the copier down an elevator shaft.

The next area that was checked was the Registration transport. New Cross Rollers (600K7301) were installed and the Servo Drive Roller (6K13290) was replaced. It was obvious that the Servo Drive Roller had about 80 million copies on it and was quite worn down. On further examination the Servo Pinch Roll Shaft (22K16940) showed signs of wear, so I replaced it as well.  Everything I did seemed to help reduce the random Fuser Wraps a little, but they never went away. 

Two days later we were called back again for Fuser Wraps. Truly frustrated, and close to a mental breakdown, we had to reexamine the whole situation.  One observation we made was that when the customer was running copies to the face up tray, they never had a jam (of any type). But once the finisher was selected that was when the problem came back with a vengeance. I began to think that there was a connection between the fuser wraps and the finisher air supply system.  One thing that was common was the two compressors in the machine and they both had to be working properly. Oh, by the way, the customer said he sometimes has a 12-143, 12-144 finisher jam. And sometimes the copy transport damages the sets. Could it be a pneumatic problem?  I replaced all plastic hose in the finisher and the problem remained. Both Check Valves (53E831) were replaced and all associated tubes were examined or replaced as needed. The Finisher compressor was adjusted to 37 pounds while running and all associated connectors were closely examined for air leaks.  At this point I was almost in tears because of the frustration, but big guys like me don’t cry! We just disappear into the sunset on our roller skates. 

I’m not sure what made me look at the Moisture Filter (53K980) but it was the next item on my hit list. The filter assembly (inside) sometimes gets clogged up and I have cleaned them with success using carburetor cleaner. Some technicians discard this filter but it’s not recommended. It protects the air system from moisture, and removing it defeats the purpose.  When the Moisture Filter was disassembled I noticed it had paper lint inside. Was it possible that the vacuum was being disturbed by this lint? After the filter was washed with carburetor cleaner and the Moisture Filter was re-assembled I began to run the copier. To my pleasant surprise it ran about 2,000 sheets of paper through the finisher with ZERO paper jams of any type.  Case closed? I had my fingers crossed, eyes and legs crossed waiting for the next phone call from my customer. Finally a week later the call was made, it was for a copy quality issue. Everyone that was somehow involved with this phenomenon was relieved and happy that the problem was finally resolved. It is also interesting to note that as the fleet of copiers and printers age, we will begin to see things that we did not see when we worked for the manufacturer.  

If you would like to share any odd problems or have an experience with any machine problems please feel free to contact me at VillageCopierNY@AOL.COM and I will pass the information along to the field. u

 

 

Raymond Cote can be contacted at Village Copier Service, 718-931-2830 • e-mail: VillageCopierNY@AOL.COM.