Mac Mini has power, but no chime, no video, and no diagnostics

I have a late 2014 Mac Mini that’s worked perfectly until today. Plugged it in, it turned on fine, and tried to install a software update. It turned off and on a few times like it’s supposed to during an update. Eventually, it restarted without the startup chime and the screen stayed black. I left it for a few hours thinking it just needed to finish the update, but nothing happened.

I tried everything most of the forums mentioned trying: resetting the PMU, the PRAM, and the SMC, booting into recovery mode, diagnostic mode, safe mode, and open firmware mode. The Mac Mini’s led would flash and the computer would turn off an back on like it registered the various commands but nothing ever happened.

Any thoughts or ideas would be appreciated, since I can’t afford upgrading to a newer machine!