Question My computer won't turn on with no activity

[CubeZone]

Hi everyone,

My computer won't turn on with no activity no fan spinning except from the PSU led so what i've did:

• Replacing the PSU with another that i know it's working but no luck
• Starting the motherboard without DVD player, RAM and HDD it maybe one of these that prevent it from starting but no luck
• Starting the motherboard without the power button and with the new PSU but no luck nothing happen just silence.

i don't know what to do next if anyone have an idea to help i well be very grateful, i'm afraid that the motherboard is dead but i need to be sure before buying another one.

COMPUTER SPECS:
500Go HDD
4Go RAM
Dual core 3.2 Ghz
HP 280 G1

 

[Lutfij]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. List them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

Seeing how this is a prebuilt, mind sharing the make and model of the PSU you swapped in? A link would also suffice. Speaking of the PSU, was it pulled out of a working system?

 

[CubeZone]

thanks for the quick response, so here we have all specs as you describe

• CPU: Intel Pentium G3250 (3.2 GHz, 3 MB cache, 2 cores)
• Motherboard: Hewlett-Packard 2B34 2.10
• RAM: 4 GB DDR3-1600 UDIMM (2 x 2 GB)
• HDD: Toshiba 500 GB 7200 RPM SATA Hard Disk Drive
• GPU: Intel HD Graphic
• PSU: 180 W standard efficiency
• Chassis: just a normal HP MT chassis nothing too fancy
• OS: Windows 7 Pro 64-bit

about the new PSU it's the same model, I've pulled it out from a similar working PC so I know at 100% it's working

 

[SkyNetRising]

• Starting the motherboard without DVD player, RAM and HDD it maybe one of these that prevent it from starting but no luck

Essential components are psu, cpu and ram. Without ram you can not start a computer.

Is diagnostic pc buzzer connected to the motherboard? Do you hear any beeps, when trying to start it?

 

[CubeZone]

Essential components are psu, cpu and ram. Without ram you can not start a computer.

Is diagnostic pc buzzer connected to the motherboard? Do you hear any beeps, when trying to start it?

even with all the components in and the new PSU I still get nothing, there is no beep no sound no led flashing no fan spinning, also i've tested with new RAM sticks and still get nothing