Nice site w/images of different printing issues:
- http://www.laserquipt.com/support/idx/26/452/article/Toner-Smearing-Issues.html
- http://www.castleink.com/_a-buy-laser-printer-fuser.html
Fusers have multiple heating elements - http://www.fixyourownprinter.com/forums/laser/8463
Cleaning Drum
- Alcohol is safe for (Brother) drums - not 100% sure about other brands, but likely true.
Some service manuals:
- http://www.fixyourownprinter.com/reference/manuals/public/hp
Startup Sequence
"Monochrome Laser printers go through a start-up routine to check for jams and make sure the paper path is clear. While the parts rotate, toner is circulated through the mechanism that transfers it to the drum, but because the drum has no charge on it, no toner gets transferred to the drum and gets returned back into the cartridge to await an actual print job where it actually gets used... EDIT: Color Laser Printers have a slightly different problem. They have to keep four colors in registration (synchronize where the colors land on the paper fed through the printer) and therefore do a calibration routine which will use toner in this process." - https://superuser.com/questions/409831/does-a-laser-printer-use-toner-when-switched-on-off
Gray background on prints
This is toner cartridge, not drum. "Discovered" this personally... this page confirms. https://www.printertechs.com/printer-troubleshooting/common-print-defects/170-defect-gray-background - not sure I understand why. Maybe something to do with toner having gone through the mechanism (B&W) too many times and losing it's static cling properties?
Tags: printing, laser, toner, drum, fuser