Defective Laserjet Toner Cartridges

[AdministratorAL]

For 6 months now I have had to replace my toner cartridges (ALL HP GENUINE BRANDED, not 3rd party, refilled, remanufactured etc.) At 70% the printing looks as though the toner cartridge is 99% empty. Sometimes it is at 70%, sometimes 90% or other. These cartridges are $450 each and i'm having to throw them away. I have about $4000 worth of partially used toners in my office now. Now a 2nd and 3rd printer started doing it. One was down to 10% but that is still about 5000 pages left. I support multiple firms and ALL of them have HP printers on my recommendation. In this office I have 8 M6XX series. Two of them have over 2 million pages printed and 10 years old. This one has 450k and is not even 15 months old when it started with this issue. I have contacted HP and they did not want to even help or hear my issue. The printer company says it's the cartridges. The supply company says it's the printers. If it was the printer, why would it stop with a new cartridge? Even for only 20/30% of the use.  I'm out of options. This printer was $2000, plus I have the mailbox/stacker (another $1000) and envelope tray and extra trays. 8 of these type, a hundred or so desktop models. Does anyone know of another company that makes a similar setup? Each printer prints about 20,000 pages a month.