eletmoraes писал(а):
The question is whether it would be risky to apply a voltage of 5v using a computer source (desktop)?
It can provide fatal destraction of some capacitors or microchips, probably, as result - your eyes will have damages.
So for searching shorted components you need current limiting around 1A. Laboratory power supply, or big resistor(for 5V `4.7 Ohms more then 5W power dissipations).
Remove 7805 and put 5V/1A power in to 2-3 pin, then a bit wait and look what a komponents will do heating.