Router power adapter work is to heat, only warm, if hot is not normal. The trip is caused by hot, indicating that the line has generated overload current. One is that the router internal fault causes the adapter to generate overload current, and the other is that the adapter's own circuit fault causes overload current.
Can find a good with the voltage adapter to try, if also hot (not warm), that is the router is broken; If not hot, the original adapter is broken. This is the easiest replacement method to troubleshoot.