Hi guys, here is very simple but useful circuit, which can be helpful when you work on laptop in Dark. Material : One LED, 5mm size, one resistor of 300 Ohm, one USB Connector wire, and other tools like soldering iron, cutter, wire etc. Steps 1- Connect resistor one end to the longer pin(Anode) of LED with the help of solder (you can also connect them by twisting both the pins), Now we have two pins spare, one pin of resistor and another one short leg(Cathode) of LED. Read More...