Are there times when you can't turn it off/on with the button?
There are two possible combinations of problems:
- Faulty power switch on the front panel
- Faulty power supply enable/disable cable.(see below)
Check the connector between the power brick and the console.
make sure that the cable is plugged all they way in
try to wiggle the cable in different positions to see if you will get a different result.
post results.