think power supply blew up

I switched my computer from one case to another. Everything working great. Had added 2 additional fans and uv lights also. Worked great. This was on Sunday. Computer has had no problems at all and yesterday my son was using my computer and it shut down. So when I came back in the house I flipped the switch on the PS and turned it on when BOOM fire and smoke came billowing out of the back . My sons girlfriend and I could not believe what we had just saw. OK so today I opened up the case examined everything and fine nothing wrong. But the PS smells pretty charred. So took it out. Going to add another PS and see what happens. But first am going to take out the lights and 2 additional fans. The ols PS was a 400W Vigor I thought it would have been able to handle this but I guess not. Does anyone know how to figure what wattage PS should be used?

Thanks

 

400 W should have been sufficient for the fans and lights.

I've got seven fans, two HD's and two optical drives with a 300 W PSU.

I'd say that power supply was just bad, or perhaps had a short. Check to see that no connectors had exposed metal that could have come in contact with anything.

Steve

 

http://www.jscustompcs.com/power_supply/

Here is a wattage calculater it should be of some help, please keep in mind that amperage is also something to consider so check your cpu and mobo manufactures website to get needed amp ratings.

Rick