Have a Rambo board. Plugged it in after being down a few weeks. When I go to turn on the Hotbed I get a red led that stays on with a buzzer noise. Any ideas?

. I've had the printer disconnected for a couple of weeks. Hooked it up to do a print, and leveled with the app. went fine until time to heat the bed. I get a red led lit and a buzzer. going to try and link the video of it at the end. I've checked every connection, replaced connectors on the HBP, even re soldiered the wire. Reloaded firmware, nothing makes a difference will do it in any slicer. m2 with 4 point, silver Z motor, bottom z-stop and dual V4's.

Makergear has no idea. 3rd or 4th board in 15 months.