I tried to power the nano from a bench top power supply starting with 1.5 amp and increasing it step by step(max current is 3A for the power supply) i didn t even see the power LED on. Now, I can not start it doesnt matter I tried. When I try to power up with micro USB the port gets hot and the barrel jack is also not powering up.
When you are trying the bench power supply or DC barrel jack, do you have a jumper fitted to the Power Select Header (J48)?
This will disable Micro USB power mode and use the DC barrel jack or 5V pins on the J41 Expansion header instead.
Note that you may also want to try setting your lab bench power supply to 5.1 or 5.2V, to account for any voltage droop from the cable between the PSU and the board.
Likewise, when using Micro-USB power adapter, there shouldn’t be a jumper on the J48 Power Select Header.
Just quited using the bench top and switched to a 5v 3A barrel jacked adapter, works fine.