Dell Dimension B110 will not boot

I'm trying to help a friend out that has a Dell dimension b110 that will not boot. When the power is turned on the lights come on for a second and the fan starts to turn but then everything dies. Not even a blinking amber light on the front. I tried a different power cord and I tried making sure none of the MB plugs had come loose.

It does the same thing regardless of whether or not the keyboard, mouse, and monitor or plugged in. No other external peripherals are plugged in.

Any ideas on things to try before buying a new power supply. I would hate for them to buy a new PS and have it turn out to be a motherboard issue.

 

Thanks for the input.

I won't be able to do that. It doesn't even stay on long enough to complete the POST.

I have all ready tried unplugging the machine and holding down the power button and even tried a different cord just in case.

 

yeah my A+ was a very long time ago and I've been out of the industry for a while too so I'm very rusty.

I did get it to stay powered up with the fans on by unplugging the the hdd & cd etc.. I assume this means the PS is putting out enough power anymore to power everything. I guess I'm at the point of buying a new power supply and hoping nothing else is damaged. Since I've had no luck finding one to test with. Does this sound about right?