Xbee S2C weird problems when burning new firmware

I got a deal on six Xbee S2C modules with Digimesh firmware. I use 802.15.4 not Digimesh but eh, just upgrade them right?

BUT when I burn 802.15.4 2003 into it, it kills my circuit board. Without the Xbee, I see all my signals on the output pins, right on the money. Put the Xbee in, and flat line on all of them, like it’s holding my atmega in reset? Have no idea how it could do that.

I should add, that right out of the box, with the firmware set to Digimesh, they are fine. The signals are all there and happiness. I can’t talk to it but at least the Xbee is not killing it.

I have all the I/O ‘disabled’ via XCTU so I am only interested in vcc, gnd, rx and tx.

Very Weird. I have never seen this before and I’ve used a lot of S2Cs.

Any clues or advice appreciated.

Thanks, Martin

I would suggest looking at what DIO lines are set for and what the internal pull up/down are enabled or set to. You may need to adjust these values.

They are all set to Disable (0)