Serial output

I have a new Up2 Pro board that I'm trying to start using. I put the UNAPAM22.bin load on the board without issue (I see reasonable output on the screen via HDMI connector), but I'm not seeing anything on the serial output. I saw HDMI output from the default load, but didn't have the cabling in place to check the serial output.
I'm observing the serial output at 115200 baud (8N1, with no flow control) and not seeing any output. I am using the USB 2.0 pin header cable (EP-CBUSB10PFL01) and simple wire connections from that to my laptop's RS232 connector. I flipped the transmit and receive in both directions as a sanity check, but I don't see anything output. Does anything seem incorrect with this setup?