I started having problems with my computer not turning on from a cold start. I would shut it down at night and when I pressed the power button, the fans would start up for anywhere from less than a second to a full 5 seconds and then the whole computer would power off. Sometimes the computer would do this a few times before it would finally power up. Later, it would take 10-20 tries to get it powered up. Today, I pressed the power button over 100 times, with no power up.
The reason I pressed it so many times was because I was trying to test each component (fan, hard drive, disc drive, etc.) to make sure they weren't shorting out the power supply. After disconnecting and reconnecting everything I finally took 20 minutes and replaced the power supply with a spare that I have never used. The spare power supply powered up my computer instantly on the first try.
Where can I test if a power supply is bad? Do you think a local shop will have a power supply tester that they might let me use for free?
The power supply worked for 2.5 years in my computer and it is an Antec TruePower2.0 480W so there is enough power (my spare is a 380W and it seems to be running fine).