Power Supply or Motherboard?

My computer recently had a failed fan in the power supply unit. I took the machine to an official computer tech company and they replaced it. I brought the machine home, used it once. I turned off the machine, unplugged it to use outlet for another computer.

I then replugged in the machine with the new power supply and nothing happened when i turned on the machine. Nothing, nada, zilch. No noise, no video, no nada. I see a green light on the chip board inside the unit so i know its receiving power, but no Action.

Is this my motherboard now, and maybe my processor. The tech's say that i need a new motherboard and processor. But i dont trust them anymore after my replaced power supply and now dead computer.

Any suggestions on the logic of what's happening with my machine? PLEASE HELP. I'm an end-user, not a tech...so I just need this all to make sense.

Thank you!

Hello there and welcome to Techspot!

I feel your pain. We've all been there. Not that sympathy makes things any better, but you have mine.

It is hard for us to tell what is wrong with your system without looking at it of course. But maybe we can help you confirm a few things.

You say you can see the green LED light is lit up on your motherboard. That's a good thing. When you push the power button, no fans are spinning at all? Not a good thing.

It could be any number of things, and the tests that need to be done involve removing parts to help troubleshoot. Do you feel comfortable doing these types of things?

Try unplugging and reconnect your power supply connections to the motherboard.

I would also test your computer case's power-on button. This is done by disconnecting the small 2pin cable from your case that goes to your motherboard, then using a screwdriver to quickly touch the two pins that that cable was connecting to. This will short the pins, and hopefully start your computer. If it does, then your power switch on your case needs replacing.

Other than that, I would try this test to see if you can get the power supply fans spinning: http://modtown.co.uk/mt/article2.php?id=psumod

If the fans on the PSU don't spin, then you have (another) dead power supply.

If the fans on the PSU do spin, then we have narrowed you down to either a dead motherboard or a dead CPU (probably motherboard)

If its an Antec PSU and a SmartPower series, the back fan on the PSU won't spin until its hot. But the fan on the inside of the case should always be spinning when the comp is on.