One of my RaspberryPi's has a cavity like this, should I worry or seal it with duct tape and use it?
@arek It's an inductor that's had a piece chipped off. It probably won't matter but it will change the characteristics of the component a bit. There's no point in putting tape on it - that won't help, and if the board still works, it'll just make it collect fluff more efficiently. If you're worried about electricity leaking out, don't - the piece that has cracked off wasn't insulation, and with the voltages and currents on the RPi being so low, there's no danger.
@cybervegan ok so there is no point of fire or overheating. The board works normal.
@arek No, it's not going to catch fire because of that. The material that has cracked off is "ferrite" which is used to form a tiny electro-magnet - I think it's part of the power regulation circuit. But as I said before, the amount of power available to a n RPi isn't really dangerous. It would be quite difficult to make something catch fire with it, and because of the stringent EU safety testing required for such devices, they have designed it with safety in mind.
@cybervegan many thanks for your sharing!