Do you know a specific number of hours to replace laserjet black cartridges?

Answer 1

Lazerjet toner cartridges are measured by the amount of pages printed at 5% coverage. Many come with 5,000 and 6,000 pages per cartridge, though most manufacturers have the larger capacity cartridges that can go up to 20,000 pages or more per cartridge. Most decent laserjets now will let you know when you start getting low on toner. I recommend Konica/Minolta because of their superior print quality. It really will depends on what you are printing.

Answer 2

you'll only have to replace the toner when the print starts to get faint until then don't worry about it you can do an awful lot of printing on one cartridge of toner a lot more than on an inkjet

Answer 3

operating hours or hours to evaporate to many size & mods. to even guess i have 1 ive never changed & 1 i change every 4-5 mos.guess which one i use the most