Toner Cartridges, Maintenance Kits and Parts

One Item
Black Genuine Toner Cartridge Standard Yield, 2 x 3,100
The LaserJet Pro M402dne uses a single toner cartridge, HP CF226AD (HP 26A).
When the LaserJet Pro M402dne reports "Supply Problem", it usually just can't communicate with one cartridge's chip. Give the printer a full power-cycle, take out and firmly reinsert the flagged cartridge, and lightly buff its metal contacts with a dry, lint-free cloth. If the message stays, install a new cartridge in the reported colour.
These quick tips apply to all laser printers. While your exact model may look slightly different, the steps are identical.