I bought my OSPi some time ago, I am guessing a couple years ago so my purchase may be close to the same time as the others in this thread. Finally getting around to changing over to this. When I powered up the board with 24VAC with the Pi installed there was a puff of smoke so I pulled the power immediately. There is a burn mark next to F2. The fuse tests ok when the meter probes are placed on the terminals on the fuse but when I put them on the pads on the board it shows open. The solder is minimal but looks connected. Obviously it isn’t. I am considering touching up the solder on this part since I work on this type of stuff regularly. Seems like this might have been a processing problem at the time since others had the same issue? Fortunately my Pi B+ still runs and appears to be ok. Please advise.