I made a USB fan to cool down my Raspberry Pi 3, (it had heating problems). I supplied power to the fan from another battery while it was plugged into the USB port.
since then it has not been working...
when I plug in the HDMI cable the Pi appears to boot for a second and turns off, it boots again and turns off..
after sometime... the raspberry pi is booting but any of the USB ports are not working I don't think there's anything wrong with the USB IC as it is the same as the Ethernet IC but the Ethernet still works
What is the problem?