Canon’s stance: Using the V5204 tool violates your End User License Agreement (EULA). Canon considers it “unauthorized service software.” However, in most jurisdictions (US, EU, UK), anti-circumvention laws regarding repair have loosened. The 2021 FTC ruling against restrictive repair practices generally protects consumers resetting their own devices, provided they do not redistribute the software commercially.
Ethical point: You are not hacking the printer to steal ink or print counterfeit money. You are resetting a maintenance counter. This falls under the Right to Repair movement. canon service tool v5204
You don’t have to play Russian roulette with your data. Try these instead: Known infection vectors
You cannot use the tool if the printer is in normal mode. You must put the printer into Service Mode manually. This process generally follows this pattern (varies slightly by model): Mitigation suggestions
Using the Canon Service Tool v5204 without being an authorized Canon service partner may violate the software’s license agreement and local laws regarding circumvention of protective measures. It is intended for legitimate repair scenarios, such as resetting a waste ink counter after physically replacing the pad—not for unlimited ink system bypass.
The number refers to the version release. Newer versions (e.g., V5400, V5500) exist, but older versions like V5204 are often sought after because they are unlocked or patched by third-party groups to work without a hardware dongle. Official versions require a costly “STV dongle” (a USB security key). The cracked V5204 has been widely distributed on forums, torrent sites, and repair blogs.