Boot 11th gen with just mainboard and external display

Hello everyone,
I only have my mainboard now and I had it unplugged for a while so it’s cmos battery died, and now I can’t get it to boot without the battery and screen connected. It just blinks at me.
Is there anything I can do or am I SOL?

Thanks

Did you put in a new cmos battery?

Do you know if your BIOS was fully updated?

I recall seeing a way to enable standalone mode without a screen. But I don’t recall if it was only for certain BIOS versions or generations. Iirc it was plugging in power, then slowing pressing the intrusion detection / chassis open switch a number of times, like 10. Slowly as in 1 or 2 seconds between pressings. You could try that. 10 presses, one second inbetween each. If it doesn’t work try 2 seconds inbetween.

I can’t find the intrusion switch on the board.

Intrusion detection / chassis open switch location: