No power even after replacing power supply

I have a desktop PC. When I press the power button the hard drive activity light blinks and nothing else.
I have opened it up. there is a light on the motherboard labelled 5v that is constantly flashing.
I've reseated the memory and there are no PCI cards.
I ordered a new power supply and installed it. No difference.

Can anyone think of anything else that may be causing this? Will the motherboard need to be replaced?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Your motherboard might be dead.
Remove memory,
remove CPU

Refit CPU
Refit memory

Remove Reset Connector from mainboard

If Video card is AGP/PCI - Remove and refit.

Try again.

Look on the mainboard for bad capacitors......

Http:// for examples.....

But definately agree with keithslater
try booting with the minimum setup : mobo + cpu + 1 ram stick, video card, PS  -->  any display ? if no, then 1 of the connected is bad, swap out 1 by 1

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
cah00tsAuthor Commented:
Thanks all for the advice, it seems to be the motherboard, I'm gonna write off this machine not worth replacing motherboard.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.