Power button flashing - dead mobo?

[local host]

Ok, so here's the story. One of my older E-machine comps one day wouldn't turn on anymore (I had it on running all the time), no fans spinning, not even the PSU, nothing. I even tested out the PSU itself and it wouldn't start, so it must have been dead, it's an el cheapo PSU too (250 watts) something you would expect from cheap manufacturers. So, I replaced it with an Antec SmartPower 300-watt, it started up to work (PSU itself), computer doesn't boot, no fans spinning, the CPU fan tried to spin very little but stopped, it's like immediately when I power on the PC it tries to move but it can't (there's nothing in it's way, I checked and cleaned it). And I also see the power button in front of the PC flashing, this must be in stand-by mode. I'm thinking my older PSU fried my mobo as well. But not 100% sure. I also had a wireless NIC connected, and it has a LED too in the back, and it was flashing rapidly as well. So great, I think I solved the dead PSU problem but now I seem to have a dead motherboard. I'm also thinking since it's mobo-related, that is why the CPU fan doesn't spin, maybe if I can connect it with a 3-pin to molex adapter directly to the PSU it will start working and that will tell me there is something wrong with the mobo itself. But the PC won't boot or anything, nor do I see anything displayed on screen so it's not really doing anything but the flashing light itself and my new Antec PSU works since air is blowing out. Even if the CPU fan doesn't spin, I'm thinking the PC should still turn on and boot, but in this case it doesn't do either.

Any ideas that can be helpful?

[JPMiller]

This VERY common...
I had a pallet of Emachines that had bad PSU's that took out the motherboard as well...
Only 1 or 2 units had anything else wrong with them..
You've got a 90% chance of a simple mobo switch and having everything else work just fine...
What are your specs?

[local host]

384MB RAM (256MB was added a long while back to it), Celeron 1.8GHZ, 40GB Maxtor HD, Geforce 4 MX 440 PCI (also upgraded a long while back), pretty much this is all the general stuff. I had the same gut feeling it would be the motherboard as well.