I inherited a PropStick USB at some point in the past. Today, I finally got around to using it, but couldn't get a basic hello world (blinking LED) program running. Eventually, I discovered that the problem appears to be with the PLL. If I set _clkmode to just xtal1, the LED blinks, but with any of the PLL modes, I get nothing. Before I toss this in the parts bin (I might still find a use for it at 5MHz), is there anything I can do to make sure this isn't really a bad PLL?
Edit: I also just tried switching out the crystal in case the PLL was having difficulty getting a lock. Interestingly, I did briefly get a blink, but the timing was very wrong and the net result is a full lockup. The fact that I did get something makes me think the PLL isn't locking (or holding the lock).