Official versions of this software are generally distributed to authorized service centers and are not typically listed on the main Canon Support website for public download.
Both buttons should be released simultaneously. The power light will blink and then stay solid green, indicating Service Mode is active. canon service tool v3900 download hot
Using the wrong service tool version or incorrect settings can permanently corrupt your printer’s EEPROM. This turns your printer into an expensive paperweight. The "hot" quick-fix downloads often come with no documentation, leading to mistakes. Official versions of this software are generally distributed
Communities like PrinterKnowledge or Resetters often share links or guides, but use caution as unofficial downloads can carry malware. Basic Instructions for Use canon service tool v3900 download hot