Quoted from Rockbiter:
EDIT: DO not try this until feedback is received from Pinball Brothers on a possible reason for this issue, per Zablon's advice below
I am brand new to the club and experience the exact same black screen upon boot completion as well. In each case, I have found that if I re-seat the HDMI connection in the backbox, the screen comes on without a need to reboot. This leads me to believe that this is an HDCP handshake issue. Has anyone suggested this as a potential culprit? A workaround for such an issue would be to put a cheap, $20 splitter in line between the HDMI output and the monitor that "accidentally" strips the HDCP copy protection from the output. I will test this in the next day or so and report back.
I tested this theory last night and confirmed that, at least in my case, the computer was not HDCP compliant (which is why "monitor 1" in the cabinet always works, but "monitor 2" in the backbox boots to black). I installed a cheap 1x2 HDMI Splitter that strips HDCP inline between the computer and the monitor and the machine no longer boots to a black screen. For me, this is huge, because I don't want to tip down the backbox, open the glass or reboot the screen to go in and reseat the HDMI connection to get a signal to the screen.
If you are looking for an HDMI splitter that strips HDCP, it can be hit or miss to find one. Here is a link to some that do: https://www.tweaking4all.com/home-theatre/remove-hdcp-hdmi-signal/
I have several of the model I am using in the photo nd they all strip HDCP.
When first conducting the test, I simply plugged the output of the computer HDMI into the input on the splitter, and HDMI 1 output of the splitter to the screen, dropping the splitter into the cabinet and running the power adapter to the outside of the cabinet and latching the backbox. Once I confirmed that the solution worked, I plugged and IEC fan out into the power supply in the cabinet and plugged the HDMI splitter into the fan out, which allows the splitter to always be on. I put the glass back on and the machine is booting to an active screen every time. Photos attached.
20220526_204519 (resized).jpgAlien Cabinet (resized).pngIEC fan out Labeled (resized).png20220526_204341 (resized).jpg20220526_135827 (resized).jpg20220526_135833 (resized).jpg