Computer won't power up. Replaced power supply and motherboard

[SirBeardsley12]

I am working on an HP Media Center M7674N. Just replaced the motherboard and power supply and it still won't power up and I'm not sure where to trouble shoot from here. I've been having nightmares about this computer and am desperate for help.

Motherboard: ASUS P5BW-LA (Basswood)

Power supply: HP-Compaq HP-D3057F3R 300W

 

[Rohit27]

It's motherboard only because if cpu would have been the problem motherboard still gives you light on it when you turn it on

To check psu direct the green and black pins 15 and 16 of 24 pin connector a and then give power to psu if fan of psu rotates psu is fine

 

[Godspeace]

This is a very simple problem that you are having its not an i think or i guess like i have read from everyone else if your computer does this its because your computer is not reading the processor correctly just simply make sure you correctly connected the processor AND secured it like everyone like to do sometimes after you have done this your pc should be working just right. If you have any other troubles with your computer just ask and i will do my best to try to help.

 

[AtradiesInc]

FIX I had the same problem bought a new power supply, power button, mother board, cpu, graphics card, and SSD drive. So I was FLIPPING OUT.

Solution: I unplugged everything but motherboard, graphics and fans.

My problem was a hard drive 100%

How do I know? well lets say i have 3 hard drives and my operating system is on the SSD drive and I knew for a fact that one worked so I unplugged the two SATA Hard drives the ones with spinning disc for those that don't know but anyways I got the DUMB idea to plug them in while it was running and first one spun up just fine and then the second one started BURNING and smoking.

Conclusion: It is some component inside that your power supply or motherboard is telling the power supply hey it don't work and will cause a fire do not run. So it is switching off the pc before it burns anything up like I almost did by bypassing it.

Results: I took the bad drive out and the PC runs like a charm.

NOTE: Do not do what I did because you WILL burn up your power supply I got LUCKY the SECOND time.
The first time i kept turning it off and on, off and on and it finally burnt up my power supply. 70$ mistake.

 

[banga199410]

I am working on an HP Media Center M7674N. Just replaced the motherboard and power supply and it still won't power up and I'm not sure where to trouble shoot from here. I've been having nightmares about this computer and am desperate for help.

Motherboard: ASUS P5BW-LA (Basswood)

Power supply: HP-Compaq HP-D3057F3R 300W