Service Cost Reduction Tips

As a field service engineer, there is one thing that has truly impressed me about copiers in general and that is the general cleanliness of the machine. This goes for almost any machine site where there is a copier or laser printer installed, and there is no excuse for it when vacuum cleaners are so readily available in the field. More specifically, it’s just the general condition of the interior when the front doors are opened. It never fails to amaze me how dirty they are inside. Maybe I’m just a nitpicker and a neat freak, but I truly believe that a good running machine is a carefully maintained and clean device, both inside and outside as well. I have noticed that with some techs (and customers as well) the interior of the machine cleanliness is not as important as the way it performs and delivers acceptable copies for the shop. Toner in general will coat almost every surface in the machine including the optics as well. And as we are well aware of, toner on any lens surface will decrease the efficiency of the device.

Keep in mind that it makes no difference to me what brand of copier or laser printer we are servicing because the interior dirt level affects all machines and that includes new machines as well. As the fleet of copiers and system printers age, the manufacturer has introduced various retrofits to address the dirt issue as it came up. Photoreceptors for the most part were not lasting as long as they were designed to last and something had to be done.

Most of the machines I have recently serviced were running without the spots blade retrofit. When I inquired where it was, the answer was pretty much the same: they did not think it was needed and it was removed. After carefully explaining to the customer how important the spots blade was, they would often balk at the cost of its installation. The spots blade was developed to remove spots from the photoreceptor belt. Spots are the one major complaint of all the end-users in the print-for-pay industry. The spots blade retrofit is available for the entire 1090 family of copiers and that includes the 4050 and 4090 system printers as well. When the 5090 family was introduced to the field, the retrofit was available for this product as well as the Docutech and 6135 families. Actually, there is a spots blade retrofit for all copiers and system printers that use a plastic photoreceptor belt. It’s interesting to note that there were several end-users that complained that the spots blade actually caused damage to the photoreceptor belt. That may have been true because it probably was not installed or adjusted properly. Before installing a new spots blade, make sure you refer to the adjustment section of the service manual and do the adjustment first. I think the customer will appreciate it when the photoreceptor belt’s life is almost doubled. You can’t argue with actually saving money for a photoreceptor belt by extending its useful life.

On your next scheduled service call where you do a full PM (Preventative Maintenance) on a machine, use your super sucker to thoroughly vacuum the interior as well. Clean all optics in the cavity with a slightly moist soft cotton rag. Keep away from any harsh commercial cleaning chemicals like Windex because they seem to leave a slight haze on first surface mirrors. Water always works best. For cleaning machine surfaces (in general) use a mild spray detergent like 409 or Fantastic. Make sure that all interior panels and access doors are firmly in place and secured. I can’t tell you how many times I found copiers with missing interior panels and it does make a difference in performance. Think about this: if the interior panels were not really necessary why would the manufacturer design the copier with them in the first place? They could save some big bucks by eliminating all these do-dads inside the copier, right? All interior panels and access hatches are there for a reason and when the engineers designed the copier, they were mostly for directing the air flow through the interior of the copier and to displace heat to the outside of the machine. With the panels removed, dirt levels are affected and then there is the heat disposition to consider as well. There are four areas we should be concerned with when it comes to service Cost Reduction.

The four cost reduction strategies are:

• Extending the charging system service life
• Preventing or reducing stray light in the optics cavity
• Flash Lamp service life extenders
• Photoreceptor service Life extender

The charging system probably accounts for about 10 to 15 percent of the parts service cost on most copiers and system printers. That may not be big bucks in maintenance costs, but if we could reduce this cost and maybe extend the service life of the charging system and make it more efficient, no one would object. The major components in the charging system include the following components: The AC and DC PWB’s, Dicorotrons, AC Voltage Power Supply, DC Spider connection harness, several DIO PWB’s, ADA PWB, and the Ozac filtration system. For the most part, these PWB’s are extremely reliable and will provide many years of faithful service. All of the parts mentioned work in concert to provide a steady current flow to the photoreceptor belt that will transfer the toner to the customer’s paper and provide a preclean current (charge) that will make the photoreceptor belt ready for the next impression.

Keep in mind that when the charging system has to work harder to do its job, the faster the charging system will fail. Note: When the charging system has to work harder generating higher voltages and currents, the faster components will fail. Conversely if the charging system operates at a lower, more conservative voltage all of its components will last longer.

Several changes have been made to the charging system that will extend the life of the components, by raising the charge efficiency, and also by reducing toner contamination. Both of these changes were introduced to the field as retrofits. The chopped Dicorotrons TAG 199 and the Air Dam retrofit TAG 222. Both retrofits have worked well in the field. It is a good idea to check the machine to see if these retrofits were installed or possibly removed or misadjusted.

Chopped Dicorotrons (125K1450)

There are two types of Dicorotrons being used in the copier today. The chopped Dicorotrons are yellow while the other Dicorotrons are white. The yellow Dicorotrons are called chopped Dicorotrons because 1.5mm has been shaved off the bottom of the dicorotron body. Unlike the white Dicorotrons, the chopped Dicorotrons are spaced 1.55 mm +/- 25mm from the photoreceptor belt. This actually moves the chopped dicorotron about .5mm closer to the photoreceptor belt and moves the coronode wire a total of 2 mm closer to the photoreceptor belt. On your next visit, check your 5090 (family) to see if the correct dicorotron assemblies are installed in the charge 1 and 2 positions as well as the preclean position.

When the Chopped Dicorotron is adjusted to 1.55mm closer to the photoreceptor belt, the charging system works easier and is more efficient; it’s actually doing the same work using less current and voltage. Because the chopped Dicorotrons are closer to the photoreceptor belt, working easier at a much lower voltage, they have an extended life compared to the old system of using the white Dicorotrons.

The HSFI interval for chopped Dicorotrons will be much higher. Charge 1 dicorotron can be reset to 2 million copies, and the charge 2 dicorotron can be increased to 3 million copies. The preclean dicorotron HSFI will remain the same at one million copies. Keep this in mind when you change the coronode wires (48K56790). With the lowering of the voltage, it means less charge on the photoreceptor belt. When it is operating at the lower voltage, it extends the life expectancy of the photoreceptor belt by delaying the occurrence of 09-203 and 09-204 system faults until much later in the photoreceptor belt life.

When we look at what we did in moving the coronode closer to the photoreceptor belt, it means greater charge efficiency, and that will mean longer life for the Dicorotrons and the photoreceptor belt.

Charge Dicorotron Height Adjustment

From my experience in the field, when I run DC-951 (with a new belt) and the AC voltage is at or near 245 volts or if the slope is less than 97 bits, the first thing that comes to mind is the height adjustment of the charge dicorotron assembly. Refer to the adjustment section in the service manual for detailed information about this procedure.

If the dicorotron height and balance is not adjusted properly, charging will not be efficient, parts will fail at a much sooner rate and your service costs will get out of hand. Please refer to the adjustment section in the service manual for the proper procedure. You will notice there are two adjustments that have to be made for the charge dicorotron height. (A) The inboard height adjustment and (B) The outboard height adjustment. The (A) inboard adjustment is by far the most difficult because adjusting the one end can throw off the other end. Therefore you should start with the outboard height adjustment first. That way you will only have to set the inboard height adjustment once.

Set the (B) outboard adjustment height using the 10mm bolt. Notice that the 10mm bolt moves a slide block that will set the height. Turning the 10mm bolt clockwise will raise the outboard end of the rail, and conversely, by turning the 10mm bolt counterclockwise, it will lower the outboard rail assembly.

Next: Set the inboard adjustment height. If you notice, there are two screws on the dicorotron assembly mounting bracket, and they are used to adjust the inboard height. The 8mm screw is attached to a PEM stud on the dicorotron rail assembly.

To lower the inboard rail height, turn the 8mm screw counterclockwise. This will loosen the screw nut and allow the rail to be lowered. But this will not actually push the rail down. The stop screw only pushes down the rail. Turn the stop screw clockwise to push the rail downward to the required height.

To raise the inboard height, first loosen the 5.5 mm stop screw by rotating it counterclockwise. Next step is to turn the 8 mm screw nut clockwise. This action will pull on the PEM stud to raise the inboard end of the rail assembly. When this is done, lower the 5.5 mm stop screw by turning it clockwise until it meets the dicorotron rail assembly. This will prevent any further up and down motion of the dicorotron rail assembly.

After you get finished adjusting the inboard height assembly, double check your work because the rail assembly may have moved because of the seesaw effect. A final outboard adjustment to balance charge uniformity will require the Xerographic test pattern. If you follow this sequence, Outboard, Inboard, Outboard, will more than guarantee that your Dicorotrons are adjusted properly at both ends.

Air dam with chopped Dicorotrons (TAG 222)

TAG 222 was designed to move the dirty air away from the coronode wire. The air dam is installed on top of the preclean dicorotron assembly. It will divert the air that is contaminated with paper lint and adhesives away from the charge dicorotron assembly. It is also intended to prevent contaminated air from being sucked down behind the stripper bar assembly and into the preclean dicorotron. This retrofit (TAG 222) will virtually eliminate 09-328 system faults. This retrofit will also enable the use of carbonless paper and quite frankly should be installed on all machines. Not many techs have noticed that there was a change to the dicorotron shield design as well. It helps to reduce contamination. The slot has been moved to the leading edge of the shield, so that it now draws dirty air in front of the coronode wire assembly. The old shield assembly design drew contaminated air across the wire. If you have any old style shields in the field, please do yourself a favor and throw them out. Reducing contamination will extend the life of Dicorotrons, shields and coronode wire assemblies. When the HSFI for cleaning the shields reaches 500K, they must be cleaned with a dry, soft clean cloth. Do not use any water, cleaning solvent or other chemicals to wipe the shields off. The thin coating will be washed off and it will render the shield ineffective and create a mess of 09-xxx shutdowns.

If you are having copy quality problems and nothing you do seems to resolve it, then try adjusting the Dicorotron height. You will be amazed how many system faults will be eliminated and the copy quality will almost jump out and touch someone. I have to admit that the 5090 cavity is somewhat difficult to work on because it’s hard to see what the heck you are doing and it’s almost impossible to get your hands into the areas that need to be adjusted. The Docutech family is much easier when you remove the ROS Assembly. There is so much more room, you could almost climb in the machine to make the adjustments. No matter what type of machine you have, I can tell you that it will be worth the effort and the customer will instantly see the difference in copy quality.

I often have techs ask me how they can resolve copy quality issues on their copier or printer. And the first question I will always ask is “have you checked the height adjustment on the Charge dicorotron assembly?” Most techs will usually admit that they did not check the height or to even check to see if the proper Dicorotrons were installed in Charge 1 and charge 2 positions. One would have to wonder why the wrong Dicorotrons were being used in the first place. I have personally seen this in many situations where the customer does his own service. The little angels mean well but they just don’t know.

Next month, we will look at reducing stray light and flash lamp life extension. And hopefully you won’t fall asleep in the middle of the article. Hey, not for anything but this is really exciting stuff. Meanwhile if you have any questions or concerns pleas feel free to drop me an e-mail at: VillageCipierNY@AOL.COM and I will personally get back to you with something. Not saying that I will actually fix your problem, but maybe make things a lot better.

Raymond Cote can be reached at VillageCopierNY@aol.com .