my computer was working well, then one day, it could not start, no power at all.
I opened the box, try to connect the power, the power went for a sec, the fans just began to turn, then the power off.
at first, I thought it was a power problem, replaced power supply, still the same situation, any idea about what is happening? I thought it might be a power shortcut, but have no idea where it happened.

thanks

haiyan

When you say you replaced the power supply, do you mean the PSU in the computer, or did you plug into a different power outlet socket in the wall? If the latter, have you checked the power cable for damage, a loose fuse, or a loose wire in the plug?

I mean PSU in the computer.
Thanks

Download a copy of my diagnostic flowcharts from here
www.erniek.eclipse.co.uk/downloads/sylvanderdiags.zip
and print them to leaf through.
Begin on the START UP chart.
You should be taken to the ATX POWER SUPPLY chart.

Check out the sites shown in note 1 on the SYSTEM chart as follows:

Manually switching on an ATX PSU [using a switch rather than the motherboard switching it on]. (http://www.virtual-hideout.net/guides/atx_psu_mods/index.shtml)
Explanation about the Motherboard switching on the PSU. (http://www.compute-aid.com/atxspec.html)
Providing an artificial load during artificial switch on of ATX PSU. (http://freespace.virgin.net/matt.waite/resource/psu/atxpsu.htm)
Background info. (http://www.epanorama.net/links/psu_computer.html)
Commercial ATX Power Supply Tester. (http://www.provantage.com/buy-22069418-antec-power-supplies-cables-atx-supply-tester-shopping.htm)