Changes

A3: 1. First the HDMI device should be plugged in and have signal output before the Raspberry Pi is started. 2.Please check if there is a video related file in the /dev file.3. Please provide us more details for us to confirm the issue.a. First please send us your order number and tell us "Call command" "Input Device" and "Using Device".b. What is the HDMI input device, resolution and frequency?c. Which version of Raspberry Pi you use?d. What is the specific calling command?e. What is the terminal error notification?