Need help please

[satlover]

I have an emachine h2742, next morning it didn't want to power up. no lights on the front. i opened it up, checked the wires, everything looked ok. I thought it was the power supply so i changed it with another working emachine t2862. No luck i dicided to put psu back to
my woking T2862, now neither one of them work. All i can see just green led on, on the mother board.
specifications for both pc :
H2742

Bus :PCI
Hard Drive Bus :Ultra ATA/100
windows xp home edition
CPU Type :2.70GHz Intel Celeron
Model : 400MHz FSB, Intel 845GV Chipset
HDD : 40.0 GB

T2862

Bus : PCI
Hard Drive Bus :Ultra ATA/100
windows xp home edition
CPU Type 2.66GHz Intel Celeron D Processor 330
Model : 533MHz FSB, Intel 845GV Chipset
HDD : 60.0 GB
than i bought atx psu 300 watt instead 250 watt,
and a mother board: Foxconn 661MXPRO S478 SIS661 ALVU8X 2DDR400
I installed the new mother board and the new psu, all i got just the fan running no lights nothing. and a black screen. I tried my two psu with the new motherboard. same thing just the fan running
what should i do next to get back and runningÉ
thank you

[flanzig1]

Try booting with the new parts without any drives or ram. Should at least see the BIOS screen.
As a side note: when a PSU dies in an Emachine, it tends to take out the mother board. So swapping parts between the working and non-working PC, may have killed the T2862.