@george I tried just the HDMI port with two other portable HDMI monitors (7inch LESOWN and 11inch Visual Beat), and they work well. The desktop monitors I tried were a 5inch Samsung and 2 27inch Dell P2715Q's. None of the desktop monitors work. My knowledge of HDMI signaling is limited, but I know the desktop monitors are capable of 4K resolution, but should sync down to the highest resolutions available to them. Is the problem here somehow? Is there a possible work-around (maybe some external hardware to force the desktop monitors to stay at 1K?)

@george Please let me know what my next steps should be? This is a brand new laptop.

@george ...I've tried different cables and different monitors with no difference.

@george No, the Type Connection activates normally, but the HDMI connection behaves as if nothing has been inserted.I've

lshw output:

(base) anernest@Banda:~$ sudo lshw -c video
  *-graphics                
       product: rockchipdrmfb
       physical id: d
       logical name: /dev/fb0
       capabilities: fb
       configuration: depth=32 resolution=1920,1080
(base) anernest@Banda:~$

I have two Dell P2715Q monitors connected to the Laptop. One is connected to the HDMI port and the other to the Type C port (via an HDMI dongle). The laptop does not recognize the connection on its HDMI port.

Laptop with connection on HDMI:

(base) anernest@Banda:~$ xrandr -q
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 309mm x 174mm
   1920x1080     60.03*+
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
(base) anernest@Banda:~$ 

Laptop with connection on Type C :

(base) anernest@Banda:~$ xrandr -q
Screen 0: minimum 320 x 200, current 5760 x 2160, maximum 16384 x 16384
eDP-1 connected primary 1920x1080+0+1055 (normal left inverted right x axis y axis) 309mm x 174mm
   1920x1080     60.03*+
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 connected 3840x2160+1920+0 (normal left inverted right x axis y axis) 597mm x 336mm
   3840x2160     30.00*+  25.00    24.00  
   1920x1080     60.00    50.00    24.00  
   1680x1050     59.88  
   1280x1024     60.02  
   1152x864      75.00  
   1280x720      60.00    50.00  
   800x600       75.00  
(base) anernest@Banda:~$ 

Laptop with connection on both HDMI and Type C

(base) anernest@Banda:~$ xrandr -q
Screen 0: minimum 320 x 200, current 5760 x 2160, maximum 16384 x 16384
eDP-1 connected primary 1920x1080+0+1055 (normal left inverted right x axis y axis) 309mm x 174mm
   1920x1080     60.03*+
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 connected 3840x2160+1920+0 (normal left inverted right x axis y axis) 597mm x 336mm
   3840x2160     30.00*+  25.00    24.00  
   1920x1080     60.00    50.00    24.00  
   1680x1050     59.88  
   1280x1024     60.02  
   1152x864      75.00  
   1280x720      60.00    50.00  
   800x600       75.00  
(base) anernest@Banda:~$ 

@george I'm afraid my hands-on capabilities are limited.'

Is there a trick to enabling the HDMI port? I can drive a monitor on the Type C, but not the HDMI.|

@george The problem appears specific to the LESOWN Type C monitor dmesg.txt, although this monitor works fine with other SBC (Orange Pi 5 Plus). Resolution of this issue is not important for me since the laptop screen displays fine on another Type C monitor I have.
On a slightly separate topic, does the laptop USB-C port support DP MST? I would like to use the laptop as my daily driver, with 2 DP and 1 HDMI monitors on my desk.

I believe I saw somewhere that the laptop supports DP Alt via USB-C. I have a small 7in USB-C monitor (LESOWN) that does not display anything when plugged into the Laptop, although the touch screen on the 7in monitor does move the cursor on the main laptop screen. Is there a power limit on the USB-C port? The laptop is plugged into a 12V 3A power supply. I Have a similar HDMI monitor that works with the laptop if I power it separately.

@george Thank you. This is very helpful.

@george Could you see how difficult it would be to connect a a CM5 EVB to the 5inch LCD in the link below. There is a pdf of the specs in the second link. I currently have it working with another an Orange Pi 5 Plus RK3588 device.

https://www.aliexpress.us/item/3256805633026060.html?spm=a2g0o.order_list.order_list_main.46.1ce31802Io5CbG&gatewayAdapt=glo2usa

https://drive.google.com/file/d/12tf1jnMa_VAKAdOYp4VAlMFsPj7Kt1BK/view?spm=a2g0o.detail.1000023.1.19f3pP0ipP0igu&usp=sharing

Curious if there are any thoughts/plans for a motherboard that replaces the 12V 3A barrel adapter with a USB-C power delivery input? This would eliminate the need to carry around a separate power supply other than a 45-65W PD that most of us likely carry around in our bag,

@george can't find the specs on the monitor other than the connectivity is 30pin FPC, 4 lane. Don't worry, I will likely order an EVB and find a compatible LCD later.

@george Do you know if the MIPI DSI interface is compatible with that of the Orange PI 5 Plus? I have a spare Orange PI LCD, so if it would work with the CM5 EVB, that would be enough justification to convince my wife to allow me to buy one. If not, is there an adapter that would make it work?

I just received my laptop and my first impressions are great, perfectly suited for my purposes. My impression is that this product is targeted for developers - would dis-assembling void the warranty? Do you have the specs and manual available on-line somewhere and a forum specific to this platform?