eMachine Power Supply failure

My parents in law have a computer bought 2 or 3 years ago from Bestbuy. It is eMachine T2542.
Last week, it did not work suddenly. The problem based on their description is:
1. When push the power button, green light blinks for a second then NOTHING.
2. If push it twice, no blink, NOTHING.
3. Wait a few minutes, push button, #1 happens again.
No signal sent to monitor.
I trust it must be the power supply. It is a PS failure. Maybe the mother board failure at the same time. Look at the post here.
I am not hundred percent sure, because they are in San Francisco.

Ok, I think it is time to get a new one.
The computer is cheaper this week. The price will rise in the Christmas shopping season next two weeks.
I will check it on Bestbuy.com, Dell.com or Tigerdirect.com.