The built-in power supply is not an open type, but the same as the external one (in a plastic case and no cooling), but the wires exit from the side through a drilled hole. In my case, the marriage came out as a result of a poor-quality alteration of the power supply, as a result, after all the settings, when the charger switched to the charging mode, the power supply burned out, which I don’t know exactly, because I built it through under warranty.See full review