I'm here with a motherboard from a Beelink SER7 7840 HS. The initial problem presented as the computer would randomly turn off while powered from the PSU and with USB PD. More recently the computer turns on but no video or fan spin with either power option.
The motherboard has since been completely removed. All RAM, SSD, WIFI, etc has been removed. Currently being powered with a variable power supply (20V). Confirmed the motherboard still powers up and will turn on via the power button but no video (HDMI or DP) or fan spin. I suspect a short or component failure. I have continuity between the ground test point and most other components and port shielding. No physical damage that I can see. Currently have it powered in a test bed and access to multimeter, soldering, hot air, etc to diagnose. Any help diagnosing this issue would be greatly appreciated.