Solved! Onkyo sr707 won't turn on and stay stay on light flashes on standby but comes on for about 3 seconds and then shuts off on

Solution
Disconnect the speakers and all the inputs and try it again.
If it still has the same problem then the problem is internal. Given the age it will not likely be worth the cost of repair.
If the problem goes away then reconnect one speaker at a time until the problem returns. That speaker or the speaker wire is at fault.
MERGED QUESTION
Question from nwois4life86 : "Onkyo won't turn on"

Onkyo sr707 won't turn on and stay stay on light flashes on standby but comes on for about 3 seconds and then shuts off on
 
Disconnect the speakers and all the inputs and try it again.
If it still has the same problem then the problem is internal. Given the age it will not likely be worth the cost of repair.
If the problem goes away then reconnect one speaker at a time until the problem returns. That speaker or the speaker wire is at fault.
 
Solution