Reprogramming Xerox 5090 or Docutech Hard Disk Drives Having an ACV Slope problem? Take the Slope Challenge!

From time to time I receive e-mails concerning problems with the ACV slope on both the 5090 and Docutech families of copiers and printers. The first time I had a bout with a bad ACV Slope it took me almost a full day to fix. In a way it was a little embarrassing because the solution is in the adjustment book. That’s right, in the book! After almost 5 hours wrestling with a Xerox 5390 with a bad ACV Slope problem I called a field engineer in Rochester. After he got finished laughing his behind off, he asked me one question: Did I check the Charge 1 and Charge 2 Dicorotron height?  I was so mortified that I would not give the guy my real name and employee number. To this day I can still hear the guy laughing like he just heard the world’s funniest joke.  The joke was on me. Funny thing was I did check the Dicorotron height, but I did it wrong. Sometimes we get stuck in a rut doing things the same way over and over again, we could do it in our sleep. The culprit was when the 5390 was converted from the white 125K1080 Dicorotron assembly to the newer yellow chopped Dicorotron 125K1450. The tech misadjusted the height because (and I’m speculating) he could not get to the adjustment screws in the back of the machine where the mounting bracket is located. To cover his tracks when the 5390 started to have copy quality problems he stuck the original 125K1080 Dicorotrons back in which complicated matters even worse. Now that half the mounting bracket is set up for the new yellow chopped Dicorotron he had the white ones in the machine.     

In section 4 of the Adjustment manual we will start with the ESV height adjustment (ADJ 9.5). This height adjustment is critical and has to be 2.1 mm from the photoreceptor belt. It does no matter whether you are using a brown or blue belt. This adjustment will ensure the ESV is set to the proper height and will give the machine its optimum distance from the photoreceptor belt.       

The next adjustment is to ensure the correct photoreceptor charging by adjusting the height of the Charge 1 & 2 Dicorotrons and making sure the Dicorotrons are balanced.  ADJ 9.6 is easy to do from the front of the copier but the back adjustments are a little bit tricky and require some patience to accomplish. Did I mention having long arms and nimble fingers could help in a big way? When working with the Docutech family, if you remove the Ross Assembly the adjustments are so easy to perform because you have a larger work area and it’s easy to see what you are doing.     

Once you have made the adjustments, there are a few more things that should be checked. For starters we all forget to check the ground brush (PL4-B1) part number 115E2200. Pinch the hairs on the brush and gently pull them. Did any come off in your hand? Is the brush in good condition, meaning does it have all its fibers? Is there any contaminant on it, like oil, grease or dirt?  When in doubt, replace it. While the photoreceptor module is out, check the photoreceptor ground strip on the belt itself. Is there any contaminant on the ground strip that may render the ground brush intermittently ineffective?  With your handy dandy trusty Ohmmeter check to see if the ground brush is really grounded. Make sure the ground wiring to the ground brush assembly is in good condition. The next item up for inspection is the pesky Metering Assembly that hides under the fuser heat roller. (PL3-E1). Remove the Metering Assembly and place it on a workbench or table. Check the ground wire that comes from the base of the blade support bracket to the top of the front cam loading arm (PL3-E3) part number 31K2970. The ground wire must be free of any insulation and has to be in full contact with the bearing on the Metering Roller Assembly (PL3-E2) part number 22K9162. All too often the static ground wire in the fuser metering assembly is open (or broken). Most techs try to do the right thing by replacing it with an insulated wire (14 gage), which defeats the entire purpose.  Poor things, they mean well

and using an insulated wire is better (they think) than a naked wire, right? Wrong. Replace the static ground wire with part number 117K11010. To all you clear thinkers out there, you can take some pride in trying to replace the wire with a piece of scrap from your tool bag because the part number is impossible to find in the parts fiche. And that’s because it is not listed anywhere in the documentation.      

The next thing on our hit list is the Metering Roller Assembly itself (PL3-E1), part number 22K9162. Take it out and place it on solid workbench. Use some paper towels and remove some of the fuser agent that is coating the roller and check the HSFI counter. Is it near replacement time? Some technicians are a little more articulate than others; when they replace HSFI items, they reset the counter. And then there are those that could care less if the counter is reset. Well if in doubt, change it.     

The Metering Roller must have a slight texture to it (it is very difficult for the naked eye to see this texture). The texture is there so that the Roller will pick up the fuser agent and send it to the Donor roller (PL3-E3) Part Number 22K27670 and then to the Fuser Heat roller. If the Metering Roller gets smooth then the Roller will not do its intended job and you get fuser wraps because the heat roller is not getting the proper fuser agent applied to it. So what do we do? Drop back ten yards and punt. Replace the metering roller assembly.     

If in your opinion, the Metering Roller Assembly looks good and the HSFI counter indicates you can get some more mileage out of it, I would check it out electrically.  Now here is something no one actually does on the Metering Assembly— check it out with an Ohmmeter for excessive resistance.  As you have the Metering Assembly on the workbench, place one probe on the bearing assembly and one probe on the Metering Roller Assembly (shaft) and check the resistance on your handy dandy Ohmmeter. The reading will never be zero because of the roller bearings in the end caps of the Metering Roller. But the resistance should be about 25 Ohm’s or less. If you have a high resistance on the Metering Roller Assembly then the Static Ground wire will do absolutely nothing to get rid of the static electricity. Guess what? The high static electricity in the metering assembly will give you plenty of headaches in other areas. Like false 03-xxx system faults and 09-xxx faults. Keep in mind that if the Metering Roller can’t get rid of the static charge (to ground). Where do you think all that static energy is going?  By the way, the 03-xxx and 09-xxx faults could be random with no regularity or consistency. You will go through the raps and find nothing wrong in most cases, and the cause is always the Static Ground Wire in the fuser assembly. Go figure! By the way, when installing a new Metering Assembly check the resistance before installation. If the resistance is high, return the roller and ask for another one. Remember that most manufacturers of replacement components do not have the high quality “final inspections” that Xerox has. So, it’s like the proverbial “box of chocolate”, you never know what you’re getting.     

Please contact me via e-mail at VillageCopierNY@AOL.COM if you would like to input any information about this topic or any other topic that concerns you.