It also includes a hidden EEPROM print feature that spits out a hex dump of the printer’s entire life story: total page count, hours powered on, even the serial numbers of the print head. Paranoid? Maybe. Fascinating? Absolutely.
Release both buttons. The power light will flash and then remain steady green (the screen will remain blank), indicating you are in Service Mode. Clearing the Canon 'Check Ink' U140 or U150 Error Message canon mb2140 service tool 2021
“It’s a zombie, Maya,” he said. “But it printed.” It also includes a hidden EEPROM print feature
He held his breath, extracted the files, and ran the executable. A gray window appeared, stark and utilitarian, with drop-down menus for model selection and checkboxes for ink pad counters. No logos. No help section. Just raw power. Fascinating
Some 2021 versions require you to click "EEPROM Clear" first. Do NOT use "Clear All EEPROM" unless you have a backup – that erases serial numbers and region data.