Solution 1 : Depressing the "Go" and "Set" buttons simultaneously while turning on the power. Continue to depress the "Go" and "Set" buttons until the LED display shows "Go Test Mode". Release the "Go" and "Set" buttons. Depress only the "Go" button again and the printer will start normally. Solution 2 : there are caked ink and dust on a wire connection that touches the grey roller of the fuser. Remove the electrical cord from the back of copier. Remove bottom tray. Remove the smaller tray that comes out the back that has a LTR/A4 lever. Open front of machine to take out toner and drum. Leave open. Take off top cover (4 screws and two wire jacks to unplug). Remove screw on back right side near bottom. Remove screw on front left near bottom that holds left side cover. Remove screw on back left near bottom (it holds a piece in the back and the side cover). Slightly pull out that back, l