Pc not booting after crash

Yesterday whilst in use my pc suddenly shut down to a weird limbo state where my connected usb appliances like mouse and keyboard were still receiving power but nothing else was happening: the hard drive stopped running and no case fans work nor does my monitor turn on. Restarting brings it back to this state and so does completely unplugging it. After some attempts there is now a red light on the back of my pc right below the powerswitch. Does this mean my powersupply has broken down? Or are other integral parts broken?

Edit: i should also mention that if the powerbutton is pressed whilst in this limbo state sometimes there is a singular half second buzz to be heard.