No post, no display, no audio, but PC powers on

[Jacob Koehler]

My computer won't post, it won't display anything and the fans all seem to be working. When I turn the PC on, the CPU fan spins for a few seconds and then stops, and all other fans work fine. I tried leaving headphones in and listening for Windows to start up, but heard no sign of life. I already replaced my motherboard and power supply in hopes that doing so would fix my problem yet to no avail. Like I said, I get no beeps, no signs of life except that it physically turns on.

I've had this PC in different iterations for 5 years now, upgrading parts as I went. The PC I have now has nothing in it that was in the original build; every component has been upgraded and many of them 2 or 3 times.

One day it was on and nothing was showing up. I turned it off and back on, but it wouldn't work. I flipped the power supply switch on and off and it was still feeding the PC power so I think that's what died, but even with a new PSU I'm still hitting a wall.

Things I've tried:
1.) unplugging every component one at a time
2.) replaced power supply and motherboard with new ones
3.) changed power cord and plugged into different outlets
4.) unplugged CPU fan
5.) unplugged all sata connections
6.) took it to a local PC shop where he concluded it was the motherboard (it wasn't)
7.) held down power button for 30 seconds after unplugging
8.) took cmos battery out
9.) flipped speaker (when I had no ram in and still got no beeps I was thoroughly confused)
10.) plugged into different monitors, tried using different ports on graphics card
11.) made sure mobo was grounded
12.) checked motherboard manual to make sure everything that should be plugged in was
13.) read every forum post and "how to fix this problem" post on this side of the internet and tried everything suggested
14.) cried in a corner of sadness

I just don't understand what it could be. Im thinking maybe my CPU is dead? But wouldn't the PC still boot into post? And that doesn't explain why moat USB devices work, but some (like my Logitec G105 keyboard) don't even get power as far as I can tell.

My PC specs:
Case: Antec 300
Old Motherboard: Asus M5A99FX Pro 2.0
New Motherboard: Gigabyte 990FXA-UD3 rev4
Old PSU: 650W SolidGear Neutron
New PSU: 750W Rosewill Capstone 80+ Gold
GPU: Powercolor AMD R9 280 3GB (won it online)
CPU: AMD FX8350 (no OC)
RAM: 8GB G.Skill Sniper 1866Mhz
SSD: 256GB Samsung 840 + 256Gb Samsung 840 Evo (no other storage)
Sound Card: Asus Xonar DG (PCI)
Generic DVDRW
CoolerMaster HypeHyper Plus

Any ideas? Honestly, I'll try anything at this point. I'm already $200 in and 2 weeks with no fix. I'm at a loss here.. Maybe my speaker is broken? Never heard of that, though..

And sorry for the wall, but I just wanted to be as thorough as possible.

Thank you guys in advance!!!

 

[Neeseius]

Definitely sounds like a dead cpu. I would have guessed either that or the motherboard but you've already purchased a new motherboard.

I would be interested to know whether or not the CPU gets warm after you turn it on.

Even with bad ram the motherboard will throw beeps like you said.

 

[Jacob Koehler]

Hmm. That's what I'm thinking too. It just seems crazy, because I just upgraded that maybe 6 months ago. But I'll try that tomorrow. Spent all that time today getting the thermal paste right and CPU cleaned, I'll be so sad if that's what it is. But thanks for the response, and I'll let you know if it gets hot when I turn it on for a sec.

 

[Dashing_star]

did you psu fan running?... do you hear beep sounds without RAM...?

 

[smorizio]

most mb now dont have mb speakers built in. old asus mb does have fault led. see if the cpu fault led is on or off. if the asus mb is still alive see if the usb flashback button and standby power comes on. if it does the only issue that cause asus not to post a cpu is bad vram.

 

[Jacob Koehler]

Hmm. Well I do have a separate speaker that's plugged in, and it doesn't beep regardless as to whether or not there's ram in there at all. And no video at all wouldn't be ram related, right? But I think it's the CPU, honestly. Everything else checks out =/