Hello everybody! I really need help!
I was programing a AtTiny13A like usually, using my Arduino Uno R3, and i just unplugged my board from usb and when i plugged it back in, all the leds were off, no sign of getting power with the UB connection. I restarted, even shut down PC, and this didn't solvthe problem. The board it's self it's ok because if i power it from outside, like with a 9v battery it's working. So : i plug board to 9v batt it's working, after this i plug usb connection to pc still working, i unplugg 9v battery, board IS WORKING but if i unplug USB and the plug back in, the board is dead, so for powering it again i need to use 9v battery and after that unplugg it so i can use usb connection . Could this be a problem with usb slot from pc? all slots do teh same! PLEASE HEELP!
I used system restore, i disabled and enabled all serial bus, and i still cannot power my arduino uno from pc's usb; when i connect arduino to pc with usb cable, all leds fluctuate and with a very very dim light and it's not recognized! I still mention my board work ok with external power source! i'm so frustrated..
Try a different USB cable.
I've tried a new cable too but it isn't working. Is it possible that windows is closing usb port because of arduino? but my phone is charging well from the same port. This is very occured
There is a polyfuse on the board. I believe it's the part labeled F1 in the schematic. Maybe it's damaged. If you have a voltmeter, measure the voltage on the USBVCC side. Someone else will have to help you locate the part; I have no idea which itty bitty rectangle it is.
F1 is ok, there is no problem with that... Very occured
I don't know what else to suggest.
If I remember it correctly, the UNO R3 board has a power source selection circuitry that automatically switches to the preferred power source. If there is any jumper pin related to that settings, kindly check that. or there may be some problem in the power selection circuitry.