one of my nano V3.0 wont power up via USB. only external power. why?
What does it do when it doesn't power up? Any error messages or other response?
doesnt do anything. it dont show up under the COM port in the software either. it only works when i plug in a external power supply to the 5V pin.
Is there anything else connected to the Nano?
Measure two different things:
- What does the 5V pin show when connected to USB?
- Measure the current when connected to the external power supply
5v pin shows nothing when connected via USB without external power.
current is good. using 4 AA battery pack to power it. measured at 5.8 V
i talked to gravitech.us techs and they said that theres a fuse on the circuit that between the usb power and the board that blew. that i have to use only the external power source for it to work at this point.
o3dodgesrt4:
i talked to gravitech.us techs and they said that theres a fuse on the circuit that between the usb power and the board that blew. that i have to use only the external power source for it to work at this point.
That sounds plausible, except that the schematic on the Nano's hardware page doesn't show a fuse... Perhaps they updated the board but not the documentation.
no clue. i see alot of SMD's on this thing and cant tell which is which or what is what.
Sounds like Diode D1 may have blown, that keeps external 5V from feeding back into USB, and if blown will keep USB power from getting in.
Looks to located near the resonator. You can use a meter and trace from +5v pin to end, and from Vusb pin coming from the pin to the other end.
@ cross roads... thanks man. ill look into that.