You will rarely see this error in a Windows pop-up. Instead, it manifests during the bare-metal boot phase. Look for the following symptoms:
Jammed staples within the stapler unit are the most common cause. 66.b3.4a error
to allow the internal memory to clear, then plug it back in and restart. 2. Check for Jams or Obstructions 📄 You will rarely see this error in a Windows pop-up
Ensure all doors and covers on the finisher are . 4. Reseat the Finisher Unit Slide the finisher unit back into the printer. 66.b3.4a error