DIAGNOSIS The F1 error is a motor communication fault. The base cannot read data from the motor in the blending container.
FIX First, power cycle the blender. Unplug it for 60 seconds. Re-plug. Ensure the container is correctly seated. Turn the container slightly clockwise until you feel it lock. The container handle should align with the power button. Confirm the container is dry and the drive socket is clean. Attempt a blend.
IF THAT DIDN'T WORK The issue may be a dirty connector. Unplug the blender. Inspect the four metal contact pins on the underside of the container drive socket. Clean them with a dry cotton swab. Do not use liquid. Inspect the corresponding contacts on the base. Repeat the seating and power cycle procedure.
HEADS UP The A3500 base will not operate without a recognized, compatible Ascent Series container. Using a non-Ascent container or a damaged container will trigger this error.