Yes, the serial cable connection works. Tested back and forth with good boards.
Had another one fail yesterday. Bounced up and down for a few minutes, then dead. When we brought it in, four leds go solid immediately, and nothing out serial port. Tried powering both POE and DC jack.
Powered by 24-26vdc through POE.
I've got all of the 411AH boards laying in a drawer. It does look like the tops of capacitors (what I believe they are) are swollen and maybe have some goo on some of them. Although I pulled one from new inventory, and there is a little stuff on top of a few.