Thanks a lot for the reply (and for deleting the duplicate post)! Turns out that I apparently had a cold solder joint (that package is pretty small for hand soldering). I now successfully blink an LED though I observe that delay(n) results in a delay that's actually 16n. So delay(10) results in a delay that's 160 mS. I'm using the same resonator that's found on the uno (murata CSTCE16M0V53-R0). Some more debugging is probably needed, but it would seem that the arduino is operating at 1 MHz and not 16 MHz -- or at least that's an obvious theory. Are there any particular reasons that this behavior would be exhibited? I can't see how any timing registers would have changed. Thanks!