The following causes and solutions should be looked into if you are unable to upgrade the Antminer KA3 firmware.
Troubleshooting Bitmain Antminer KA3 firmware upgrading and repair guide.
This article will explain security firmwares for the Antminer KA3 and address some frequently asked questions about security firmwares. IMPORTANT: Avoid attempting to upgrade any unauthorized Antminer KA3 firmwares from outside sources, as doing so would cause miners to malfunction and immediately void your warranty. What is the Security Firmware? The security firmware was created …