Need help troubleshooting Melzi 3D printer controller

[CharlieWorton]

Yeah... this one is kind of a hail Mary pass, but I figured I'd try it.

I bought a replacement electronics board and display controller for my 3D printer, after the original board died.  The board I bought is this one:

https://www.aliexpress.com/item/BIQU-New-3D-Printer-MELZI-Motherboard-Reprap-MKS-MELZI-Controller-MainBoard-2004LCD-Board-For-Prusa-I3/32760696867.html

Got it all hooked up, plugged it in, got a red LED beside the power in port... and nothing else.  Dead display, no activity when I rotate the controllers or push the reset button on the board.

Checked the polarity on the 12VDC in power (it was correct) and tried it again.  Same result.  Disconnected everything except the power in, got the same result.  There are two fans controlled by the board, and one should be spinning constantly.  It was dead.

So I don't know where to go with this.  I tried contacting the retailer, but they haven't had the courtesy to respond.  MKS doesn't really have an English component on their website, and certainly nothing resembling a help section.

So, crap.

Anyone have any thoughts?

Thanks - Charlie