Tech Tips

GENERAL

CLEANING TOOL FOR MIRRORS
Everybody has been asking how to clean the hard to reach mirrors on copiers e.g. Canon 1215/1500/2020/2120 etc. Canon advised that you use a Mirror Cleaning Tool. You can actually fashion/make your own tool. The tool is about 4 to 5 inches long and has a curve on both ends and both ends has a foam/or a smooth cloth on it.  If you have a Canon Np 1500 manual it is on page 4-7.  Using this tool will solve a lot of your copy quality problems.  

REPLACING FUSER FILMS
Be aware when replacing Canon fuser films that the ends are different and installing backwards will cause you wasted time and/or travel. Case in point: installed a new film on Canon C200D. The film has a brown band on one end. This end is wavy and not cut straight. This end is designed to go at the end where the tracking sensor is. It reads the back and forth movement of the film to adjust the tracking solenoid. Installing backwards ( straight cut end ) will cause immediate tracking faults and adjustment will be ineffective. Hope this saves someone else from having to do it twice.

ULTREX CONNECTORS
In the process of trouble-shooting an electrical problem, ultrex connectors need to be checked. These connectors fit over the pin base on a PCB. If you experience a problem with one of these connectors, then take a file or micro-cutters and trim a small amount all the way around the bottom of the connector. This will allow the connector to fit further down on the pin base and give better connections.

The plating on the ultrex connectors used in Canons will flake off, causing cross connections. This will result in any number of strange electrical problems which mimic PCB failures. If you have access to an ultrex connector tool, which looks like a small screwdriver with a very thin two pronged end, insert it around each individual connection. This will clear out the cross connection caused by the flakes and tighten the connector as well. Spraying the connector with contact cleaner an blowing it out works sometimes too.

LIGHT / UNEVEN COPIES
A light or uneven copy can result from crud buildup on the doctor blade of the developer, (or toner, on monocomponent machines) unit. To correct, vacuum out dev.section and remove doctor blade and clean . Adjustment is controlled by copper shims made onto doctor blade.

DRUM & BLADE CROSSOVERS
The drum and cleaning blade out of an A30 canon cartridge will fit straight into a np-1010 / np1020 copier. This means a cartridge that runs out of toner at obout 3,000 will have a drum & cleaning blade the can see another 1,700 in an np-1010 or 1020 Also the canon pc-850 drum and cleaning blade fit right into the np-6016 drum unit, so when the pc850 cartridge runs out of toner around 10,000 it still has another 40,000 left in it. Also the charging roller is interchangable. The drum and blade also fit the np-6030 but you need to change the drum ends. They pop out with a piece of rod about 5mm thick bent to an L shape.

SMALL DIAMETER DRUMS
On many Canon small diameter drums where the drive for the registration rollers is also supplied by the drum, the drive gear in the drum itself can sometimes spin freely causing paper jams in the registration area. The solution is to remove the gear and epoxy back into place. I have noticed this problem in 1010/1020's most often but have also seen it happen in 1820/2020/2120's and 6025/6030's any small diameter drums should be suspect.

CORONA WIRES
When replacing spooled corona wire, instead of using a hex key like all the books say, I take a 6 or 7 inch piece of coat hanger and form it into a J shape. It's much easier this way.

UNEVEN DENSITY
Sometimes you can fix this problem by sanding the DV Roller with a fine grit sandpaper. You must sand it evenly of course.

CFX-L4000/4500

I have found these machines to start to groan while printing. Canon has come out with a plastic piece to stick on the back bottom center of the machine. I personally have had no luck with this fix. What I do is fold up a piece of paper into a small square, about 3/32" thick and stuff it under the metal plate located under the back fold down door. What this does is pushes down on the "off white colored" floating seperation system enough so that the rollers can't rub against it and cause the "groan/vibration". Make sure that you put the paper square in far enough so that it doesn't interfere with the transportation of the paper from the cassette to the printer area. I have about 30 machines in service right now with this fix and am getting no call backs for the noise.

CLC'S

CLC (All)
I recently had a problem with a grainy, sandpaper image from a 350. After checking the obvious: i.e. Bias connections, High voltage outputs, I started wholesale parts exchange with no resolution. A bulletin board reader got me to go back to the bias. I found the bias was not turning on. I replaced the DC controller and that solved the problem. (Of course you should check the connections first) 

COLOR BALANCING
When color balancing a Canon CLC,always make sure the optics and CCD assy's are clean (use Soap and water- I use one drop of Ivory clear diswashing detergent in 4oz of water),then set LAMP in service mode to specs,do WSAMP adjustment, then do CCD adjustments. It is very important that LAMP be set properly.

DRUM REPLACEMENTS
When replacing the drum and cleaning blade in the CLC's especially in the CLC 200,300,350. Use padding powder on the drum and the blade, then sprinkle a little in cleaner assy behind the cleaning blade. When you think you have applied enough padding powder to the system. Repeat the process again. It takes very little drag for this cleaning blade to roll and wipe out the drum.

CLC-500
Copier indicates connect printer,no dc voltage. Resolder dc p/s contacts or send pcb to hytec.

CLC-500/550
When you get a code 110 (laser code) remove laser cover and check the window to the mirror. It gets a buildup that looks like little beads. Remove mirror and blow out with air. Be very careful with the mirror. Fixes the problem 85% of the time.
To fix the problem of build up in the window, make sure the lock for the laser is up and not touching the top of mirror. Its hard to tell if its up all the way.

GP-200

GP 200 series canon copiers can't handle color pictures when duplexing. Any color pictures in a newsletter or just printed by itself can cause the gp to lock up. Symptoms are the applications crashing, the gp 200 print led blinks forever and will not allow any more print jobs to go through. when the IP board has the 45.02 update an E 675 code will occur have customers convert to black and white pictures before printing.

NP-120

COPY QUALITY
You can adjust copy quality resolution by backing off the primary wire and turning up the secondary. Play with them until you get the desired result.

C-122 and NP-6012 Crooked copies, black line lead edge, and mis-registration

I will make something more proper but on the plastic rib guides in front of PS roller there is a two-tier level. Find some approx. 1mm thick or slightly lighter plastic cut to about 1" by 8.25" put two-sided tape on the back. Lay it on the rib guides down against the bottom of the high edge of the feed-in end.  The paper must slide easy on the plastic so it must be very smooth. This stops the crooked copies and mis-registration of the paper.   My experiment is brand new.  FYI, the size of what I used was dictated by the plastic I had lying around.  The length seems to be ok if a little narrow but not less than 7.5" long. It is possible the width could be longer or narrower but this works so far. I did try several ways some others worked and some failed. It helps that the one test machine I am working on is in the shop and has the problem quite badly.  A couple of other things. The plastic I am using has 2/16 slots cut 1/2 deep in the 1" inch with and are facing the PS roller. I am not sure these are necessary or they may be a necessity

NP-120/125

TEST COPY
Wait for 30 minutes after plugging in an NP120/125 for the Photo drum to warm up. The standby mode maintains it normally. This uses pressure fusion and funny toner.


NP-120 /125

Problem: Partial Blank Copies. Canon 120-125 copiers will occasionally generate service calls for "Partial Blank Copies. This can be an intermittent problem but will produce a copy with a blank top from 1 to 4 inches. This is caused by melting foam seals on the blank exposure assembly. They turn into a gooey mess and cause the light blocking assemblies to stick.
Solution: Remove the entire assembly and clean with a good solvent. Manually activate the solenoid to check for sticking, then replace. This fix should take about half an hour.

NP-150/155

CODE E3
If you get a false E3 code you may be able to fix it by soldering a connection between the two main terminals on the board under the right hand side cover.

FUSER
You can increase the life of the fuser busings by rotating them 180 degrees when one side wears.

ELECTRICAL
If the copier starts running by itself, flickers or general acts erratically, try soldering the connectors on the DC power supply.

NP-270

WRINKLING PAPER
Problem: Wrinkling paper out of the fuser unit
Solution: There is an end feed guide plate just before the fuser rollers. Hard particles of toner build up on this plate causing the paper to get caught and twist as it enters the fuser unit. Sliding the plate to the left will remove it. Then scrape it clean with a sharp edge tool or knife. This will resolve the problem.

COPY QUALITY
Problem: allagator skin pattern on your copy.
Solution: The number "2" Corona unit is shorting out. Rewire with Canon gold plated tungsten and replace the blocks. Most of the problem comes from the rear block.

EXPOSURE LAMP FUSE
Problem: Exposure lamp fuse keeps blowing.
Solution: Clear or replace the filter in the cooling fan to the left of the optics unit, also confirm that the fan is turning.

VARIOUS PROBLEMS
Problem: Noise dirty copies and toner spilling out of the cleaning unit.
Solution: The toner used in this model will pack up in the cleaning unit and form very hard rock - like stones of toner in the cleaning unit causing a bind up of the gear breaks on the back of the cleaning unit. Replace the gear and check the bushings on the cleaning unit drive shaft. Most of all befor you put it back in the machine make sure that you dissassemble the entire unit and scrape out all of the hard toner.

E-3 CODES
Problem: Erattic E-3 Codes. The older scanner clutches in this machine were known for slipping after 50K copies. Replace it with a new scanner drive unit.

E-O CODES
Problem : Emergency E-0 code temporary fix due to a blown thermal switch in the fuser.
Solution: When it is necessary to get the customer up and running while you are waiting for the thermal switch to arrive you can remove the old switch place it in a refrigerator freezer and it will reset itself.

COPY QUALITY
Squiggly blank lines running down the length of the copy, black spots all over copy. Replace the number 2 corona wire and gird with Canon gold plated wire.

C-300

Problem: Drive block gears stripping out (specifically the developer drive gears within this block assembly)
Solution: Apply a drop or two of Ames typewriter oil on to the ends of the developer roller, and spin the oil into the developer felt seals. Be careful not to apply the oil to the image area of the developer roller, if this happens polish off the oil or finger prints with a dry Sontara wipe. The gear damage appears to be caused by an increase in friction of the Developer unit rotating. Apply the oil and/or replace the felts approx. 60K. Empty the drum used toner collection area every 60K as well.

NP-1010

COPY QUALITY
Light copies
Check to make sure that the springs that hold the dv unit to the drum are both in place.( Front and back).
OPTICS
The last mirror is extremely hard to clean. To clean it you must access it from inside the machine. There are 4 screws that hold up the slit glass holder. You must also remove the lamp assembly next to it. Be careful to replace the mylar slit shield and the actuator correctly.
BLANK COPIES
If you are getting blank copies try the transfer corona 90% of the time is the problem.

NP-155

WRINKLING COPIES
Problem wrinkling copies. Replaced the usual upper and lower fuser rollers checked and adjusted for even pressure between rollers. Still wrinkling. Solution was the paper drive roller on the transport immediately before the fuser assy was slipping. I had to remove the rubber roller off of the drive assy clean both inside and out and then I double side taped the rubber to the drive roller so it couldn't slip anymore. Problem solved. Berny Buta (The Copier Doc)

RUNNING CONSTANTLY
Problem: Copier running all the time, no panel lights, won't go into warm up.
Solution: There is a brown 5 volt wire going to the power supply located on the top right side of the machine. The solder connection on the PCB under that wire breaks causing no 5 volts. Resoldering repaired the problem.

NP-1020

PAPER FEED
Jams Pre-Registration
You may need to add pressure to the Pre-Registration Roller Springs.

SCANNER PROBLEMS
When powered up, the scanner does not initialize but scan motor can be
heard turning. Motor trying to overdrive scanner to left.
Clean the connector at the scan home sensor.

NP-1215

JAMMING
When copies slow or stall between drum and fuser, before replacing transport belts, try cleaning and lubing all the shaft bushings on the bed.
COPY QUALITY
Streaks
DV unit spacer rollers may be worn. Replace.
PAPER FEED
Cheat the interlock and watch the paper go through. If paper stalls or slows between the drum and fuser you probably need to replace the transport belts.(Rule out obstructions first.)

NP- 1215/1520

UFR Residue
Cleans off very easy with brasso

NP-1215/1520/2020/2120

UFR RESIDUE
When the top fuser roller in the fixing unit gets covered in the residue left behind by the mono component toner use a scotch bright plastic green kitchen scouring pad. It will clean that top roller like new in less than 1 min.

UFR RESIDUE
In regards to cleaning UFR's with green scrubby pads; STOP IT! The pad will still put tiny, unnoticeable scratches which will then collect the toner faster. It appears to be brand new but you will soon return to clean it again. So save time and effort and replace the UFR, it only takes about 30 minutes.

NP-1218

DRUM DRIVE
The drum drive gear is made of plastic and some times breaks due to vibration from the DV unit. Change mag roller and developer bearings and make sure nothing is binding the DV unit.

NP-1500

JAMS IN THE PAPER PATH
Adjust vr 306 on main pwb or take out metal roller bar from the transport belt section and coat it with rubber coating or recoat tape.

NP-1530/1550/2020/6020

Patchy copies and occasionally banging, insuffient pressure on the rear dev racking cam.
Remove dev unit, remove right cover, undo two connectors on the front & rear of the paper inlet guide, remove two screws front and rear that hold that guide in, and waggle out of the machine. You should now be able to see the dev racking shaft, take out the single screw which holds the dev racking handle, you can now turn the shaft round to gain access to the sprung screw which holds the cam on, remove ,stretch spring and reassemble. Should take about 5 minutes.

NP-2000'S

NOISE
Broken teeth occur on all 2000\3000 canons if the drum cavity is not emptied periodically due to the cleaning unit binding up and increasing drag on the drum. The first indication is usually a clicking noise.

NP-2015

Problem: Chain noise from main drive chain rubbing on plastic caused by worn plastic bushings at the fuser drive side and the registration roller end.
Solution: I've had great results replacing them with " oilite " bushings from other applications. Four bushings are needed. The fuser end takes about 15minutes and the registration end about half an hour.

SKEWED COPIES
Canon 2015 copiers that have a skew in the copy can be fixed by stretching the spring on the registration roller on the end where image is shortest. Too much tension is causing the reg.roller to feed faster on that end. A small screwdriver wedged between to coils spreads enough to make a difference, though it may take two or three adjustments to correct the problem.

COPY QUALITY
Blurred image. Some times the fuser drive chain can become stretched. You can fix this problem by just removing one link.

NP-2020

FALSE JAMS
I HAVE FOUND THAT THE UPPER AND LOWER PAPER FEED SOLENOID HAVE FOAM PADS THAT DEGENERATE TO A GUMMY TEXTURE THAT DOES NOT RELEASE QUICKLY ENOUGH THE CLUTCH CATCH THIS CAUSES THE 'D' FEED ROLLERS TO ROTATE TWO OR THREE TIMES, CLEAN THESE OFF AND MAKE SOME NEW PADS FOR THE SOLENOIDS FROM THIN FOAM MATERIAL WITH SELF STICK, FIGURE 260 ITEM 3 IN THE 2020 PARTS MANUAL. NO POINT BUYING A NEW SOLENOID.

LIGHT COPIES
If copier gives light copies intermittently, have seen several machines that mounting screws become loose on transfer corona block which is attached to rear of transport assembly, causing intermittent loss of transfer corona voltage. Remove transfer unit and tighten screws. Check for deformed contact springs.

LIGHT COPIES
When getting light copies check to be sure the transport assembly lever is not going past it's stopping point. If it does the transfer corona (which is part of transport section) will sit about 1/8 of an inch below where it is supposed to, causing light copies. There is an adjustment under the blue/green lever that you can see if you remove upper cassette. Adjust it so the transfer corona ass'y locks in just right. For some reason this adjustment can wiggle its way out of position... probably from customers slamming transfer section back into place.

Scanner power flex cables
I recently had a call-back on a Ca
non 2020 due to an open expose lamp thermo fuse. Approx. 1k earlier I'd replaced the scanner flex cable due to an intermittent open. Since the thermo fuse is an intentionally weak link, did getting hammered by dirty surges contribute to its demise? In the future I intend to replace the fuse when replacing flex cables! Cheap insurance!

NP-3000'S

NOISE
Broken teeth occur on all 2000\3000 canons if the drum cavity is not emptied periodicaly due to the cleaning unit binding up and increasing drag on the drum. The first indication is usually a clicking noise.

NP-3025

DRUM DRIVE
Broken teeth. DV unit binds and causes drum to freeze up, causing broken drum drive gear teeth. Replace binding parts or entire DV unit as necessary.

NP-3025/3525

SCAN PROBLEMS
Carriage moves about one inch and stops, then you get a fault code. I've found this to be caused by the photo-interrupter on far right of the optics assy.

NP-3050

PRE-REGISTRATION JAMS
Cause: The spring on the pre-registration sensor can get weak and allow the flag to bounce causing a jam. Solution: Wrap the spring around the flag one more time increasing the tension and stopping the bounce
PAPER JAMS
Jams in vertical pass assembly. Some times the deck motor runs too fast. Replace the motor.
COPY QUALITY

PAPER JAMS
With 10 bin staple Sorter attached, paper jams at the fuser.  This is caused by the sorter pulling the fuser door away from fuser. I don't know why they mounted the bracket on the fuser door.
You can fix this by putting a small washer behind the fuser to move fuser out to make the gears mesh.

NP-3050

Light areas down one side of the copy
Cause: This can be caused by fuser oil vaporizing and migrating up and condensing on mirrors 2&3.
Solution: Clean the mirrors with varsol, then Isopropyl Alcohol and then use glass cleaner to finish the job.
Prevention of further occurrences: You should put small pieces of black electrical tape over all of the small holes in the deck over the fuser.

NP-3050, 4050, 4835, 3825

Black lines on copy, drum has white haze on it. Looks like drum lube. Replace drum blade. Beware of faulty blades from some places.

NP-3225

DRUM DRIVE
Broken teeth. DV unit binds and causes drum to freeze up, causing broken drum drive gear teeth. Replace binding parts or entire DV unit as necessary.

NP-3525

DRUM DRIVE
Broken teeth. DV unit binds and causes drum to freeze up, causing broken drum drive gear teeth. Replace binding parts or entire DV unit as necessary.

NP-3725

SKEWED COPY
If 11x8˝ copies are frequently skewed, check the rear hinge pin which holds the movable registration guide & lower reg. roller. It has a tendency to crack and become loose, causing a loss of pressure on the rear side of the reg. rollers. If pin is no longer available, you can swap it with one of the duplex refeed guide pins (they don't have pressure applied to them). DRUM DRIVE
Broken teeth. DV unit binds and causes drum to freeze up, causing broken drum drive gear teeth. Replace binding parts or entire DV unit as necessary.
PAPER FEED
Jamming may be caused by slippage of the one-way bearing on the feed roller shaft. Clean or replace as neccessary.

If paper starts to feed from cassette and then feeds back in, clean or replace clutch on separation roller shaft.

NP-3825

PAPER TRANSPORT
Transport bed fan maybe worn causing jamming. Replace fan if neccessary.

NP-3825/3325 NP4835

BLACK STRIPES
Black Stripes across the copy Original Illumination lamp blinks.
Cause: The flexable power cable has fractured from being clamped too close to the end kinking it and not allowing enough slack. Solution: Replace cable making sure that it does not kink during the full travel of the scanner.
Prevention: Check all of your Canon Machines for this problem and adjust the clamps to prevent kinking of cable. The "Black" cable seemed to cause the most problems. Canon has since changed the cable to a better one.

NP-4540

Problem: Copy very light with banding from front to back.
Solution: The transfer corona assembly needs to be seated correctly after the corona wires are replaced. If it is not this problem will occur.

NP-4835

E-80 CODE
Problem: E-080 CODE after working on color developer changer unit.
Solution: Replace Main PCB DC Controller if you unplug the color changer unit to service it and thenm plug it back in while the machine is pluged in the main PCB DC- controler will become defective

E080 CODE IN DISPLAY
Solution: Sensor Q-5 in the duplexing unit gets dirty fast also goes defective faster that the other sensors.

Laser class 5000 "start again" message.
This message is a paper timing error
1. Check paper tray: Make sure that the guide is set for the paper loaded in the tray
2. Clean the paper-detect sensors.

3. Clean and inspect the clutches
4. Check pcb connectors
5. If problem still persists, it is probably the main board.

NP-6000

COPY QUALITY
Jitter on copies. Scan wheels are made of nylon and some times crack. Replace as neccessary.

NP-6012

1/2 BLANK COPIES
WHEN THE CUSTOMER TRIES TO INSTALL THE TONER FOR THE FIRST TIME AND KNOCKS THE DEVELOPER OUT OF POSTION THIS WILL CAUSE HALF BLANK COPIES. WHEN REPOSTIONING THE DEVELOPER MAKE SURE YOU MAKE CONTACT WITH THE ANTENNA AT THE REAR OF THE DEVELOPER THIS WILL SOMETIMES BREAK AND THE UNIT HAS TO BE REPLACED.

E-210 CODES
On the 6012 the lens will not find home. More often than not it will only happen every other time the power is turned on. The problem is in the drive assembly. Just order a new one and be careful replacing it. It can be a real bear.

PAPER JAMS
If customer complains of jams at reg. roller, or finds no paper, check the exposure lamp.

NOISE
If you are stuck with an awful grinding noise when paper is being picked up from the cassette, look to make sure that the paper size plate (the one that sets the paper length) is in the proper position. If it is out, the paper can slip back ans allow the pick-up roller to rotate against the cork on the cassette lifter plate. This causes an awful noise and jamming problem.

E000, E001, E002, E003 CODES
To reset these codes perform the following:
Remove the front panel and be careful not to bend or break the flexible
cable connected to the panel and the DC Controller.
Turn on the copier and short the jumper wires JP3 and JP4 on the dc
controller pcb with a screwdriver.
The count ratio indicator on the control panel turns on 'F'. When 'F'
is turned on stop shorting the jumper wires
Turn off copier and turn it back on and its then reset.

NP-6012f/6412f
Doc-Feeder Malfunction
Ok who had the bright idea of putting a feeder on a 12cpm machine?  This is looking for problems.
The most recent symptoms are not always recognizing paper in the doc-feeder. The cure I have been finding is the gray communication wire in the back causing faulty erratic problems one way to make sure if this is it is to wiggle the wire a little and see if the paper will get recognized. If so, just replace the wiring harness. I have replaced 3 in the past month and it has solved erratic problems.

NP-6012F/6412F
Problem: These feeders have a problem of not recognizing a document when its placed in the ADF. It is NOT the wiring harness as another tech tip described.
Cause: The problem is in fact, caused by the micro switch located next to the left hinge of the feeder. When closed, it still has a small resistance (around 6~8 ohms). This
small resistance causes erratic document detection errors.
Solution: All that has to be done to correct this problem is to bend the micro switch actuator outward so when the hinge is closed, the switch is closed tighter.

NP-6016
E007 CODE
E007 Code indicates damaged fixing film, but often is caused by the rear of the machine latching completely when clamshell is closed. This causes the gears that drive the film to not quite mesh, so the film doesn't move, or moves too slowly. This usually happens on ADF models, as they have heavier shocks for the Clam Shell. Before replacing film, which is a pain, try pushing down on left rear corner of machine to see if it runs.

NOISE
Chatter Noise: I have found that the gear cluster for the manual bypass has a gear that rattles from side to side causing secretaries to curse you. Replace the whole gear assy and they will praise you once again!!!

E007 CODE
E007 fixing unit fault in the upper fusing unit of a canon np-6016 needs new upper fixing belt or fixing unit.

NP-6016/Selex GR-1060  The "add toner" lamp blinks when toner is full.
Check connector at the rear top of developing unit. This connector must connect the rubber blade assembly in rear side and through the rubber blade it must connect to the mag. roller in the front side. Sometimes when dev. roller felts and rubber blade was replaced, a little bit of toner dust lays on connectors and connection is lost.  At first, light copies come out and next, the add toner lamp comes on. Check this connection best with the multi-meter.

6025 -30 paper feed problems
When getting intermittent paper feed problems the first thing to do is change all of the feed tires even if they look good. After spending much time trying to find feeder jam causes, this usually solves the problem.
 

NP-6050
DUPLEX JAMS
Canon 6050 Duplex Jams are sometimes caused by the LTR size paper cutting into the user side deflector on the fuser assembly (the white Duplex deflector which is right after the fuser on the fuser drawer ass'y). What happens is that the deflector is designed with European paper in mind and the American size paper is a bit smaller and causes it to cut into the front deflector and sometime this cut in the deflector causes the edge of the paper to catch and jam. To fix this I have been taken the deflector out and with a hack saw blade carefully cutting around the front and rear deflectors and twisting them off, therefore taking the two deflectors totally off. Canon has come out with a new deflector ( it is black in color ).

DOC FEEDER JAMS
If you find that the document feeder jams when using it to copy a 2-sided original check the pin on the rear side of the left paper feed flapper, it may of broken off. To fix this problem without having to worry about it happing again drill a hole through the flapper the same size of the pin and glue a hex wrench cut to the same length that the pin was. (Here is the key though, the hex wrench must be just slightly larger than the hole, this will prevent any chance of it coming loose.) I have had to do this to 6 NP6050's so far because the flapper has been hard to get. However it works so well I will not be replacing the flappers.

Canon 6050 RDF jams, this is caused by the fact that the machines are designed with European size paper in mind and that it is just a bit larger than US size paper. This causes the American size paper to cut into the front feed paper ribs on the right side cover of the RDF . The paper is actually cutting into the rib and causes jams or the originals to get a dogeared edge. The fix for this is to snip off the front rib or ribs on the right side cover and file them smooth.

NP-6050
Always replace upper f. Claws when replacing fuser roller. Also replacing it @ mid life of original oem roller life will extend its life by 35-50 percent.

NP-6050
Upper fuser roller interchanges

Canon NP-6060 upper fuser r. can be interchanged w/6650 ufr.

NP-6060
Notice your copies are very light and putting the darkness up high or even putting the drum potential up doesn’t help. Try re-soldering your lamp regulator and you should if all things go right that you’ll need to adjust everything right down again. Np 4835 HVTdc also gives similar problems and also dark bands on page. Do the same thing. Re-solder joints. I find a lot of the time that this is the case with most PCB's "dry joints"

NP-6085
RDF
6085 is the same as the 6050 therefore, they have the same problems. So see TIPS under 6050 RDF Jams !

NP-6521

EXPOSURE LAMP PROBLEMS
Fluorescent exposure lamp has a heater wrapped around it. The heater, which doesn't wrap all the way around the circumference of the lamp, has a cut-out in the center of it to allow a sensor to detect lamp intensity. If the heater slips and blocks light to sensor then a E221 code or light copies may occur. If the heater twists on the lamp then uneven side to side density may result. Best fix is to use double sided tape to secure heater to lamp. Make sure cut-out on heater is aligned with the sensor and make sure heater doesn't cover the clear slit on the fluorescent exposure lamp.

NP-6521

If the shield on the scan lamp partially obscures the lamp sensor the machine will pause before copying. After pressing the
print button the lamp lights but the machine will pause for several seconds. It won't be as slow with the AE off. The fix is the same as the one for E221, tape the shield in the proper position. There's a tip in this section about the right way to do it.

NP6650

Mystery Jamming
Remove the separator tires from the LCC, it has double feed prevention claws at the top anyway. Also remove the lower fuser roller cleaning blade, if you are using a good quality web and a sleeved lower roller you don't need the blade. If the unit is in a well ventilated area remove the BIG ozone filter, don't remove if in a stuffy room, the ozone exhaust will feed back in through the optics cooling vent and deteriorate seal and sponges over a period of time.

FUSER JAMS
For fuser jams on the 6650, make sure that the entrance guide to the fuser stays clean. Even a small amount of toner build-up will cause jamming, skewing etc.
EXIT JAMS
For fuser jams at exit or in the inverter section especially when duplexing, check the latch pins that hold the exit door closed. If they are only slightly loose, this will cause jamming.
LIGHT COPIES
Cause: Ozone deposits built up on Primary Corona Assy. this is the brown deposit that builds up on the grid and stainless steel shields
Solution: I find that you can remove this film with a water based cleaner and then I spray in a light mist of isopropyl alcohol to remove the moisture (alcohol will cause the water to evaporate and dry faster) I do this as the first operation of any PM to let the assy dry completely. This same operation should be done to both the retransfer corona and the trans/sep corona assy. This will help the coronas to give even charge to their area.

NP-7000

COPY QUALITY
Jitter on copies. Scan wheels are made of nylon and some times crack. Replace as neccessary.

NP-7550

COPY QUALITY
Skewed copies. Check front scan support roller. Loosen the retaining screw and rotate the roller housing to correct skew.
PAPER FEED
Clean clutch units if replacing paper feed rollers doesn't fix problem.

NP-7558

LIGHT JITTERS
Check rubber mirror mounts in optics. After a few years ozone causes these to turn into goo. One more reason to clean the ozone filters!

8000 SERIES

Problem: Machine shutting down erratically
Solution: There is a five volt power supply located in the rear upper left side of the machine. This goes into shutdown losing your 5 volts. Replace and problem is solved.

NP-8000

COPY QUALITY
Jitter on copies. Scan wheels are made of nylon and some times crack. Replace as neccessary.

NP-8530
CONTROL PANEL LOCKOUT
If the control panel on 8530s locks out, try cleaning the connectors on the control panel PCB and DC controller with Blue Shower or other contact cleaner.

NP-8530
PROBLEM: In READY mode copier TURNS scanning lamp ON and LOCKS keys.
DESCRIPTION: - Turn copier ON - Copier goes into WARM UP - After reaching 150 degrees INIT AL ROTATION doesn't go ON - After reaching 170 degrees CONTROL PANEL begins blinking and SCANNING LAMP stays ON.
SOLUTION: Rear side (bottom center), there is a PCB shaped as a mirror L. There is a 24 pin connector at the bottom left of PCB. Sometimes the metal rear cove pushes wires from connectors and creates this problem. So simple, but I had this copier down for a month. I replaced power supplies( 5V and 24V), DC controller , etc) and cost me $200 in unnecessary board repairs. Live and learn!

NP-8550
COPY QUALITY
Skewed copies. Check front scan support roller. Loosen the retaining screw and rotate the roller housing to correct skew.
PAPER FEED
Clean clutch units if replacing paper feed rollers doesn't fix problem.

PC SERIES

CANON PC 6, 7 and 11:
PROBLEM: Scanner fails to drive.
SOLUTION: Bad solder on Scan Driver Board.

BLACK COPIES
The large black guide that holds the left side of the A15 or A30 cartridge in the machine has two plastic pins on the rear frame side. If one of these pins breaks, the guide can flex enough to cause the exposure slit on the cartridge to not come in contact with the tab that opens it as it is slid into the machine. The result is no light can strike the drum.

BLANK COPIES
Do a half-way test. If there is no image on the drum
remove the transfer corona. Check for cracks in the charge blocks where
the wire goes under the covers. They can be repaired by cleaning the
block and attaching a piece of electrical tape over the bad spot.

COPY QUALITY
Skewed image. Some of these models have a set screw on the end of the scan mirror assembly that wears and may need to be adjusted occasionally to correct skew.

Blank copies. Check the drum ground contact and clean as necessary.

Blank copies. HVT may need to be grounded more securely. You can do this by placing a star washer on a screw between the HVT and the frame.

PC-3

SCAN PROBLEMS
Problem: Clicking noise after scan reverse. Clutch wont switch scan direction.
Solution: The scanner rail spreads out causing a lot of up and down play in the rail. This play causes the return micro switch not to get activated. You can replace the rail but I did find that the outside of the rail can be squeezed in slightly and the inner rail can be spread out to resolve the problem.

PC-6,7

Paper Jam
Paper leaves tray about 1-2 inches and jams. After cleaning feed rollers but before changing them, take a piece of medium grit sand paper and sand the guides that the paper follows as it leaves the tray and goes into the copier. Overtime, the paper can hit the same spot enough times to cut into the plastic and cause it to hang. Also seen this same problem on Sharp Z series copiers and HP printers.

PAPER FEED
If paper keeps getting hung up right out of the tray, check the tray itself. Sometimes the plastic tabs that hold the tray components (guides) in the tray break and don't hold them down anymore, so the snubbers release the paper unevenly and it skews as it begins to feed. You can drill small holes and tie-wrap them back down again.

POWER LOSS
If the copier intermittently shuts itself off or won't power up, check the fuser door. Sometimes the door gets pulled open by the catch tray. Check that the latch is tight and tighten or repair as necessary. You can also just tell your customer not to use the catch tray as a temporary fix.

POWERS ON BUT STAYS IDLE AND DOES NOT INITIALIZE
Very frustrating !  Scanner does not ever move or initialize which is the actual cause of the problem. Fuser does attempt to heat but only for a few seconds and never enough to come to ready. The cause for this is a lack of ground between the Scanner drive transistor and the mounting plate. Remove the Scanner driver board (left rear of the machine) and scrape the transistor flat (metal) side where it grounds to the frame and also the frame itself. This will provide better contact for the scanner motor to drive and come to home position which is necessary for the machine to properly initialize. Maybe use some conductive grease between the transistor and the frame ?

PAPER FEED PROBLEMS
When having paper feed problems or broken tray, replace paper tray with tray from Canon PC 25 or PC 20. Works great !!!

 

PC-7,11
BLANK COPIES
I have had quite a few calls asking me to help them with the copier, they the cartridge in and close the machine and a blank paper comes out or after they cleared a jam, when they closed the machine again it gave them a blank image. The solution to that is they should reopen the machine and take out the cartridge and reinsert to the snap (till the where it wont go anymore) and try it again.

PC-20,25

BLANK COPIES
90% of blank copies are usually caused by shorted Transfer Corona Unit,
Remove Transfer Corona and run a test copy. A very faint copy will appear.

MORE BLANK COPIES
Blank copies are more likely to be as a result of lamp regulator fault than psu.

Blank copies. If none of the usual stuff works, try replacing the whole transfer corona assembly.

Blank copies. Could be bad DC power supply. Replace if necessary.

If you suspect the D.C. power supply, put a star washer between the D.C. P.C.B. and the frame it's mounted to.
Subject: Canon pc 20/25 blank copies

PC-25

ELECTRICAL
Problem: Erratic electrical activity. Panel flashing & shutting down and jams.
Solution: On the right side of the machine is a small power supply with a circuit breaker on it. The ground contact on the bottom of the board connecting to the frame needs to be scraped and placing a toothed lock washer between the board and the frame tightly secured resolved the problem.

COPY QUALITY
Blank streaks on copy running down the length of the paper. Transfer unit wire is new. The Varistor connected to the transfer unit shell need to be replaced. Make sure all contacts are very clean.

PC-65

WHITE BANDS
Problem : Pure white bands approx. 1" wide, lead-to-trail, on both sides (LTTR.).
Cause: Drive pin (black plastic) [protrudes skywards].
Solution: Needs realignment with drive channel (provided by the lens driver assembly).

PC-720 THROUGH 790 (POSSIBLY 850)
LIGHT OR BLOTCHY COPY
Blotchy Copies: Change transfer corona roller (do not clean or touch)
Light Copies :  Repair or replace power supply board  # FG5-4826. (bad soldering)  And re-adjust lamp and AE settings.

PC-740/770
Jamming @ Registration Area
Found both Canon PC's with feed problems. Would start to pass paper but would stop @ registration roller. Traced to exposure lamp burnt on only 1 end. Replaced lamp #FH7-3272 fluorescent lamp & problem was resolved.


 *All the information above is based on our experiences. Office Land has no responsible for any

   problems due to perform these technical tips.