Ink Level Reset Instructions for Canon PG 40 PG 50 CL 41 and CL 51 cartridges

# Cover only the top row of contact pads that you see with tape.
# Put the cartridge in the printer, and it will give you a message "Cartridge Not Inserted".
# Remove the cartridge from the printer.
# Now cover only the top two rows of contact pads with tape.
# Put the cartridge in the printer, and it will again give you a message "Cartridge Not Inserted".
# Remove the cartridge from the printer again.
# Carefully, remove the tape that you had covering the top two rows of contact pads on the electronic strip.
# Place the cartridge back into the machine. The machine should now show that cartridge with a full status.

Rex Rotary config page instructions

Rex Rotary copiers and printers are similar to Ricoh copiers and printers, and will even sometimes have the same model numbers.  If you know your Rex Rotary devices model number, you can look it up on the Ricoh cross reference chart to find the comparable Ricoh model number, then you can get the Ricoh configuration page instructions for that model.  For example, a Rex Rotary C7521n is the same as a Ricoh CL 3500N.