I have an Antec 550 Basiq power supply. My system has been having random crashing and lockups, so I decided to test it. I put a volt meeter on the plugs as instructed herehttp://www.lockergnome.com/it/2005/03/02/learn-how-to-diagnose-power-supply-problems/
Not bad, as far as the article goes. It's dated 2005, and very obsolete. The orange wires should be 3.3 volts.
Unfortunately, the only real way to test a PSU is by substituting a known good PSU of adequate capacity.
I would never buy an Antec Basiq. I think they cut too many corners in that line to meet the price point. I have three computers with other Antec models (one 8 years old) in them. To be fair, I have to admit that I'm never on that tight of a budget.
Exactly when do you have the random crashes? What are the rest of your system specs?
jtt is right. Random crashes can be caused by memory or thermal problems. Also buggy drivers - especially video drivers.