VCC and GND of the device are shorted implies that the device is burnt out. This might be due to the power network you have or simply a bad product from origin.
Of course, we can't say much without seeing a detail schematic. As an initial guess, I would consider
- massive Vcc overvoltage events, e.g. > 7V for a 5V device
- latch-up triggered by input voltages at any pin beyond the supply rails. Due to lack of current limiting means, the rated clamp current is exceeded.
If you have a high speed component that would be a possible reason. If so you should provide an independent regulator for those high speed components that can handle its requirements.