If you actually smoked the chip as you said it will be a dead short. Most ICs will fail dead short on their power rails if there is an issue like reverse voltage.
Jerry On 18 October 2017 at 12:40, Josh Malone <[email protected]> wrote: > Thanks. I tested an unpopulated board and it showed no issues w/ power > traces. It must be something I did, but it seems that it must have > been under one of the ICs. Bugger. Will have to depopulate them and > check. > > Thanks! > > On Wed, Oct 18, 2017 at 1:22 PM, Stephen Adolph <[email protected]> > wrote: > > Josh, > > my suggestion would be that, short of a board defect which is rare but > can > > happen, you have a solder bridge underneath one of the chips. > > You also can have a chip soldered in the wrong orientation. that would > make > > a big problem. > > > > Steve > > > > On Wed, Oct 18, 2017 at 12:47 PM, Josh Malone <[email protected]> > wrote: > >> > >> All, > >> > >> So, I just let the magic smoke out of my third REX build. Not sure > >> exactly what went wrong yet. Hoping for a bit of help investigating. > >> > >> 1) Has anyone built a functional REX with the pre-castellated boards > >> from OSH park. I don't think this is the problem, but hoping to verify > >> > >> 2) Can someone measure a resistance for me? I'm reading 2 ohms across > >> 3.3v and gnd. You can measure this between the '3V3' and 'GND' > >> connections at the JTAG port. > >> > >> Clearly 2 ohms is not right, and I haven't found what the problem is > >> yet. I've de-populated the board of everything but the CPLD and flash > >> and the resistance is still 2ohms. > >> > >> Thanks, > >> > >> -Josh > > > > > -- ----------------------------- Jerry Stoner [email protected]
