Problems with MFP Xerox and Samsung: warms up too long and font is faded
Symptoms include: printers a.k.a MFP Xerox/Samsung when turned on spend suspiciously a lot of time for "warm up" (2 to 5 minutes); suffer from faded fonts, double/triple image, black and white lines. Perhaps the problem lies in the failure of conductive transfer roller bushing (sleeve) and/or transfer roller. If you already have some experience doing small repairs of any kind of equipment (assembly-disassembly) then on the example of Xerox 3119 we show how to get rid of these problems. It's relevant for all types of devices like Samsung SCX-4200, Samsung SCX-4220, Xerox PE114e and other similar models.
So, first we need to disassemble Xerox 3119:
1. Unscrew the screws on the back cover, then remove it.
2. Open the front cover, it is secured with clips so use some force to remove it. Unscrew the screws of the side covers.
3. Hold the edges of the side cover, pull it down and on itself, thereby removing the clips (marked in green).
4. Perform the same operation with the second cover. Keep in mind to unplug the connector (right cover).
5. Unplug all connectors. Remove scanner unit (upper part).
6. Unscrew the screws that secure the top cover.
7. Then unscrew mounting screws of laser unit.
8. Unplug all the connectors of the laser unit. So, now we've reached the transfer roller (marked with a green star).
9. Electrically conductive bushing (green lines).
10. Gently push the holder of the transfer roller (yellow arrow). Remove the roller and bushing. The roller must be thoroughly cleaned with soap and running water. Next, the roller should be dried in a warm (not hot!) place over night.
11. Now let's concentrate on the bushing and the spring underneath it. Bushing should be replaced with a new one, and should be wiped with alcohol.
The bushing itself consists of a special conductive plastic, and eventually loses its conductive properties (high voltage has an ill affects on the structure of the material and hence on the "conducting chains"). In a normal state the resistance of the bushing should be between 10 to 100 ohms. The device during the initialization calibrates the HVPS block according to currents, and because of poor contact with the transfer roller, the device can not fully do it, and hence, the display we see that says "wait, warming up".
If you do not have a new bushing or you basically want to make the repairs without getting new parts, let's apply the following method: around the bushing wind a thin copper wire with a small cross-section.
Another variant is make your own bushing, by carving it out of a graphite brush from a motor of a regular vacuum cleaner, also you can remove it from a used HP/Canon cartridge (FCe16) bushing PCR (black, conductive). There are some that recommend to apply conductive grease to the bushing - bad advice, it was proven that it sticks to the toner, and all the repairs went down the water spout along with the spider and all your work.
Sometimes even with a worn out bushing the device is ready to print very quickly - from 5 to 15 seconds after worm up. In this case, the resistance of the bushing is the tens of megohm, but the font is faded - the reason is the same, the bushing of transfer is worn out.
So don't hesitate to replace it.
New or repaired ("modified") bushing is put back, along with the dry transfer, reassemble the unit in the reverse order - and in most cases we'll have an excellent result. But if this doesn’t work just read on!
It sometimes happens that replacing the bushing doesn't help. The cause may be a faulty HVPS board, and this can be verified only by replacing it with another, but this time functional, HVPS board.
Also very unpleasant situation occurs when fixing the bushing or replacing the HVPS board doesn't help. It is recommended in these situations, to remove the spring that extends from the THV contact to the transfer bushing (pictured below), and thoroughly wipe all beneath it, then insulate the spring.
We hope that you have done everything right and everything works and prints. Thank you!