A loose HDMI port on your Switch Dock can cause intermittent display issues. First, check the HDMI cable—use the official Nintendo cable, as third-party cables may not fit securely. If the port is still loose, don’t attempt to fix it yourself, as you may damage the dock’s motherboard. Nintendo offers official dock repair services: contact their support to send in the dock, which typically costs $50-$80 and takes 1-2 weeks. Third-party repair shops also fix loose HDMI ports for a similar price, but ensure they use genuine Nintendo parts to avoid compatibility issues. If repair is too costly, consider buying a new official dock (around $90) or a reliable third-party dock (like Anker) that supports 4K resolution and fast charging. To prevent future damage, avoid yanking the HDMI cable—disconnect it gently by holding the connector, not the cable.