If the 4421A is stuck on the connecting screen, first check that the cable and connectors are fitting properly. If possible, try testing the equipment with a different cable. Additionally, inspect the pins on the connectors to ensure none are bent or damaged. If the issue persists, and the 4421A device continues to display a "connecting" status after utilizing a different cable, please fill out a Return Merchandise Authorization (RMA) form. You can submit an RMA request through the provided link.