PSUs (in the UK at least) are required to have some form of overcurrent protection in case of an increased load due to a fault. Forms of protection include thermal protection, current limiting, output shutdown and the basic fuse.
Thermal protection, a simple temperature cut-off that resets itself.
Current limiting means just that, as the load increases the current is prevented from rising above the max allowed and in extreme conditions the PSU will trip or the output voltage will fall to zero.
Shutdown means the output will switch off until the load is removed and sometimes requires a PSU reset.
If this post refers to your laptop fault then that clicking you can hear is possibly either the on-board regulator or the PSU thermal trip resetting