Desktops forum: desktop wont power up

While you replaced the PSU and it shows no action, it may actually be doing something or lack of it. You also didn't provided any details of your PC, just what is it? Details do matter, ram, age, model, video type, USB connections, etc..?

With side cover off and AC cord pulled for at least 10mins., replug AC. Hit power sw. and observe before doing that the innards of the PC, what if anything happens. Of course, recheck your connections, take nothing for granted. Also, closely inspect the mtrbd., for anything out of the ordinary, etc.. Come back with results. Also, you may search on these forums previous posts on problems like yours.

ok, pc specs, about two years old, Ibuypower built -

Processor - Quad core AMD Phenom™ II X4 965 Black Edition Quad-Core CPU
Motherboard - [CrossFire] MSI 790GX-G65 -- AMD 790GX CrossFire Chipset w/7.1 Sound, Gb LAN, S-ATA Raid, USB 2.0, Dual PCI-E MB
Memory - 8 GB [2 GB X4] DDR3-1600
Video Card - NVIDIA GeForce GTX 295 - 1792MB - Single Card
Power Supply - 750 Watt -- Power Supply - SLI Ready
Hard Drive - 500 GB HARD DRIVE -- 16M Cache, 7200 RPM, 3.0Gb/s - Single Drive
Sound Card - Creative Labs Sound Blaster X-Fi Xtreme Audio
Network Card - Killer Xeno Pro Gaming Network Card

Since post i have reset CMOS and tried moving ram around. i have checked connections many times. the mobo is getting power i can see the light. i have also plugged in a different hard drive to see if that was it. when i press the power button no sound is made, and for a split second the leds for the internal fans come on, then nothing. no beeps no fans starting up, nothing. instant failure.

since it last worked, some component fails. After retrying with the bare minimum of hardware (that's the motherboard, RAM and CPU) I'd start trying another CPU. If that fails, I'd try a new motherboard (with the old CPU, if possible).

Might be a typical job for a repair shop, depending on your competence and hardware stock.

Kees

I'd yank the audio and network card and fall back on the motherboard supplied units for a test run.