Bizhub C35 miss feeding

Once again I got a call to fix a jammed Bizhub C35 that the customer could not find the jam. The simple answer to this is that the machine has not jammed. If the user had actually read the screen they would see that the message on the screen says that there has been a miss feed in the tray and can the user check the paper in the tray then open and close the right hand side door. It does not say the word "Jam" anywhere.
The problem occurs when the machine tries to feed the paper during printing but is unable to pick up the sheet from the tray and hence a miss feed. Since no paper actually moved from the tray there is no jam but the error message on the screen looks similar to that of a jam with the message to open and close the right hand side door. The reason to open and close the door is that this is the way that the machines controller clears the error message from memory. However, since it looks like a jam screen most users expect to find a sheet of paper inside the right hand side door and believe that the machine is broken because there is none.
So for these cases I explain that if there is a miss feed displayed on the screen then they need to check the paper loaded in the tray and this is most likely what they will find:

The most common cause is that a sheet of paper is sticking out to the right from somewhere in the middle of the stack of paper. The part that sticks out folds up along the inside of the tray. As the top sheets are fed into the machine the stack decreases until the sticking out sheet gets between the top sheet and the feed roller. I don't know how this happens but it has happened many, many times.

Since the feed roller is mounted to the paper tray it is easy to test the feed by turning the roller by hand. If the paper doesn't feed check that the top sheet is touching the roller. If it is check for the sticking out sheet in the middle of the stack.

P.S. I just had this same problem on an Okifax F-305 so it is not just the Konica machines that do this. The Oki also made a loud shuddering noise as the feed roller skipped across the top of the paper.

Tray 3 horizontal transport jams

I have a Bizhub C654e with jamming in the tray 3 horizontal transport unit (J-1730). 

The C654e and C754e or their black and white counterparts have large capacity trays for the bottom two trays. Tray 3 can hold 1500 sheets of 80gsm and tray 4 1000. The trays are position side by side with tray 3 on the left so to get paper from tray 3 to the vertical feed path on the right of the machine a hozontal transport unit is fitted above tray 4. This is why tray 4 is smaller.

J-1730 jams in this horizontal transport unit are just the same as jams at the vertical feed and mean that while paper pick-up was good there was a problem with the paper feed or separation rollers. So first thing is to change the worn looking feed and separation rollers. Easy.

Still jamming.

When removing the jammed paper I can see that the paper has not yet entered the horizontal transport unit so the problem must be in the feed station. There are a set of horizontal feed rollers in the feed station itself so I pull the cover off to have a look but didn't find anything suspicious. While the cover was off I removed the feed sensor actuator to have a look to see if the sensor was dusty. This is what I found:

If you look at the face of the actuator you can see a groove cut into it at about the same height that the paper would hit it. 

I had a look at the paper that had jammed and could see marks on the edge at the position of the sensor. Next I manually feed paper into the sensor to see if it would catch on the groove. Yes it does.

It seems that paper hitting the actuator at the exact same spot 200 thousand odd times had worn a groove that was causing the jams. Strange that I had not seen this before. But I had never looked for this before either. I will now.

I sanded and polished the face of the actuator and ran some paper through the machine from tray 3 and could no longer get it to jam so I will definitely need to remember this.

A cockroach on the laser

I got a call to fix a Bizhub C364e that was reported to not be printing all of the text on documents. When I arrived I was shown samples of some black and white documents with voids at diferent locations on the pages. So to start with I printed out the C, M, Y, K gradation test prints and this is what I got:

The magenta print was from the first try. I had no idea what caused the marks so I pulled the drum out and had look at the charge unit but didn't see anything so I shone my torch into the machine to have a look at the developer unit. I couldn't see anything on the mag roller but am sure I saw a shadow move under the cyan unit. After a bit more looking I didn't see anything so tried the gradation prints again. This time the colours were fine but I had a void through the black as seen in the above picture. So I am thinking what the hell could cause a void to move from one image unit to another?

I pulled the black drum out and shone my torch into the machine and again saw something move over the laser glass and disappear under the drum mounting rail. So I got down lower and looked into the hole for the laser glass cleaning wand and got face to face with a medium size cockroach. It was sitting on top of the laser unit and seemed to be dazed. My guess is that it was walking back and forth across the laser unit occasionally blocking the path of the lasers and causing the voids in the prints. The dazed look was probably because the roach had been blinded by the lasers. 

As I watched it crawled right and up toward the registration rollers. I had to get it out because I didn't want it to make a mess on the laser glasses or worse. What would happen if it got into the high voltage supply behind the image units? 

Since I last saw the roach heading toward the rego rollers I opened the right hand door of the machine and was sure I saw something disappear into the tray 1 feed station so I pulled all that out. Nothing there. So I pulled the registration assembly out. Still nothing. So it must still be on the laser unit so I pull all the drums, developer units and image transfer belt out but I still can't see it. Next out comes the power supply and then the laser assembly.

I look into the now hollow machine and see no sign of the cockroach. 

I look down at the laser unit in my hands and can see a leg poking out from underneath the end of the laser unit. I carefully tip the laser onto its side and the cockroach immediately runs and hides in a small hollow space next to one of the skew adjustment motors. Aha, cornered.

At this point I think I should mention that I have an irrational fear of anything with more than four legs. Insects really creep me out, spiders are worse and the bigger they are the easier it is see how freaky looking they are. So being this close to a decent size cockroach is really getting my heart pounding. But this copier must be fixed!

So I stick my screwdriver into the hole and flick the cockroach out. It went nuts on the floor trying to find a place to hide and I dropped the laser unit and both tried to jump on the cockroach while at the same time jump away from it. Unfortunately with all the parts I had pulled off the photocopier spread around the floor around me the cockroach had many places to hide. 

So there I am in the middle of this office shoving copier parts aside with one foot and stamping the floor trying to end this cockroach. I am sure I didn't impress any of the girls working there. But I did get the cockroach.

After that I put the copier back together again and everything works as it should. 

I am just glad it wasn't a big Huntsman spider in there or I would have had to call another tech to come and get it out. Either that or write off the machine.

Tape on toner cartridge

This is quick but it made me laugh. I was working on a photocopier and noticed a used toner cartridge on the floor next to the machine waiting for the cleaner to hopefully pick it up. What got my attention though was the packing tape was still covering the shutter on the cartridge.

So the toner had been taken out if it's box and jammed into the machine without the user spotting this tape. Amazingly the tape tore and stretched to allow the shutter to open and the machine to work. If it didn't I am sure I would have been called to fix it.

An Unknown error

Yesterday I got asked help with a Bizhub C754e that had some scanner problems. Most mornings the machine would have a C-9401 error when first used. According to the manual C-9401:

While this seems to indicate that the exposure lamp is the fault I was asked to change the CCD first. We didn't have a new CCD in stock but we did have a Bizhub C654e that was being stripped for parts that I could take the CCD out of. 

I went out to the C754e first thing in the morning to find the scanner had been locked out and the history showed that the C-9401 error had caused this. The actual swapping of the CCD was straight forward as was getting it lined up.

However when I powered up the mc I was given a C-D291 error. When I looked up the code in the manual I found an entry for the code but the only description there was "Unknown". What does that mean?

I knew that it was most likely caused by the CCD so I checked that all the cables were seated correctly but that was ok. The only thing that I could think that was different between this CCD and the original was the firmware. The manual never mentioned updating the firmware when installing the new CCD but the manual also doesn't mention anything about using a 2nd hand CCD either. 

The machine already had the latest firmware loaded on it as did the machine I took the CCD out of but I loaded up this firmware again, rebooted the machine and now it works.

So if you have a C-D291 error or other unknown error try reloading the firmware, you might get lucky. Also changing the CCD fixes the C-9401 error.

Power cord instructions

I had a comment on my IH power supply post about what power cords are used on these machines so here is page from the installation instructions which may help.

Paper behind the trays

At least once per week we will get calls about a copier that has an error after a jam with a code C-0202, C-0204, C-0206 or C-0208. These codes will be displayed on a bright red screen that states that one of the paper trays can no longer be used. The message continues to ask if the user wishes to continue to press a "Continue" button on the screen then prompt the user to turn off then on the sub power switch which is on the control panel. If this is done as instructed the copier will work as normal except the affected paper tray will no longer be selectable. Usually the user will panic at seeing a scary red screen and call us or will fail to read the on screen instructions and turn the copier off and on at the main switch and will have the error again once the machine starts up.
The C-020x errors are common to all Konica Minolta Bizhub copiers and printers. The code refers to the paper tray lift motor malfunction and the last number refers to which particular tray is affected, 2 for tray 1, 4 for tray 2, 6 for tray 3 and 8 for tray 4. The error occurs when tray has been pushed into the machine and then engages the motor behind the tray that lifts the paper into the feed rollers above but the paper does not reach the upper limit sensor within a set period of time. If the machine tries to lift the paper in the tray but waits for a longer than reasonable time for either sensor that shows that the paper is at the correct height or the sensor that shows the tray is empty then the machine presumes something is wrong and stops.
While I have had a couple of lifting motor gearbox couplings fail in the last few years and once had an upper limit sensor fail these are fairly rare. Just about every time I see these errors it is because of a sheet of paper getting behind the tray and preventing the lift gearbox coupling with the lifting plate in the tray. The paper usually gets behind the tray if there is a miss-feed from the tray and the sheet ends up between the feed and separation rollers and the tray is then pulled out and the stuck sheet stays in the machine and falls behind the tray. When the tray is then pushed back in the sheet is pushed into the lift motor. To prevent this the on-screen instructions for clearing the jam and the instructions in the user manual both state that before pulling out the tray the lower right hand side door should be opened and any paper pulled out. But not many users read the instructions.
Removing paper from behind the tray is not as easy as it sounds even if know it is there. This is because of the group of switches behind each tray that detects the position of the guides in the tray to automatically detect the size of the loaded paper. To prevent accidental damage to these switches by people reaching into the machine the designers of the machines added brackets at the front to prevent the trays from being removed. The brackets are in different places on different models or even on different trays but are easy to spot if you know what you are looking for.
Once the paper is removed opening and closing the front door of the machine will clear the error code or if the tray has been locked out then switching the machine off and on at the main switch will allow the tray to be used again. After the tray can be used again the cause of the original jam should be investigated to prevent the chance of the same error happening again.
So the lesson is if you have a jam always check for paper in the right hand side of the machine before pulling the trays out.