Resolved Help/Idea - MBP M1 Pro/Max No Display Output in HDMI with Clamshell mode

[TinyMito]

I wonder if anyone experience the same issue with MacBook Pro 14/16 with M1 Pro/Max chip; if you only plug in HDMI cable to your monitor and a mouse via USB. Close the MacBook Pro lid down into clamshell mode.

The display will never wake up, as if the computer is just sleeping. No matter what I do with my mouse, and I did try with keyboard plugged into it with lid close. No reaction.

If I use the USB-C DP-Alt mode, the display wakes up as it receives the signal in clamshell.

This is by design? Any ideas?

 

[TinyMito]

Nevermind, it needs to be plugged in to the power. Otherwise, my MacBook Pro won't wake up.