Hello, i have an arduino uno, and the voltage regulator burned (working on a project i feeded it with a 12V motorbike battery), so i unsolded the regulator and solded a 7805 voltage regulator. I connected Vin to a 9v battery and measuring the 5V output, it has 2V. It cant be the regulator again, so i think it could be the micro. It is possible that i have burned the micro? Or what can be the problem? Thanks
Could be the reverse polarity protection diode has gone open circuit.
Could be the 3.3V regulator dragging down the 5V.
Could be the autovoltage selector.
Could be the USB/Serial chip.
Could be the 328P.
Could be a dead 9V battery - they don't supply much current.
With unpowered board, if you measure resistance from 5V to Gnd, do you see a number in the tens of Kohms, or something much, much lower? If lower, start removing components one by one until the resistance goes back up.