C is for capacitor
It goes without saying that you should unplug the power cable and battery while doing a repair, but simply removing the power source doesn’t mean there isn’t a chance of getting shocked. Capacitors store charge. They can be found on power supplies and scattered throughout circuitry. While a shock from most capacitors in consumer electronics isn’t fatal, they can still give you a decent jump. When working with electronics, be sure not to grab capacitors directly or touch them with any conductive material.
If you plan on replacing a capacitor, you may need to discharge the capacitor first. If that’s the case, use our guide to build a capacitor discharge tool. Discharge time varies with size. It is important to give the tool enough time to discharge the capacitor completely.