1. Disconnect all the speaker wires from the back of the receiver. Turn the receiver on.
2. If it stays on then one of the speaker wires was shorted or one of the speakers are bad. Reconnect them one at a time and turn the receiver on. When you connect the bad wire or speaker the receiver will shut down. If after you connect them all if the receiver now stays on then there was a short where the wires were connected to the receiver that you repaired when you replaced them.
3. If the receiver goes into protection with no speakers connected then disconnect all the inputs and other wires and try turning it on again. This isn't likely to make any difference. If the receiver continues to shut down then it has an internal problem that would...