microcontroller short circuit test
Consider Port A (just another name for your port) and write a code to Toggle A.0 after 3 seconds while the rest of the pins of this port  and other ports are set at LOW. Use multimeter between A.0 and GND and If you see voltage fluctuations and not a constant zero voltage , meaning its fine. Repeat this for the rest of the remaining pins.Before performing this make sure that power pins and oscillator pins are not short circuited. If there is some availability of an internal RC oscillator, use that instead of external  

It's obviously time consuming since this is what I came up at my own and probably this forum will answer you some other great methods.