Computer Won't Start (Only Sign of Life is Green LED on Mobo)

rizii

Honorable
Apr 27, 2012
1
0
10,510
Hi everyone,

I recently built a computer with the following specs:

CPU: i5 2500k
Motherboard: Sabertooth Z77
PSU: OCZ Fatal1ty 750W
GPU: Powercolor PSC+ 7870
RAM: Corsair Vengeance Low Profile (CML8GX3M2A1600C9) 2x4GB
Case: Antec 900
HD: Plextor M3 Series 128GB SSD

History:
Once assembled, I attempted to start it up but it wouldn't POST - the cpu and case fans whirred, but almost immediately stopped. The computer would try again, and the computer would go on an infinite loop. I eventually fixed this problem by resetting the CMOS, and reseating everything.

Current Problem:
The computer then worked fine for about a day - I played some graphics intensive games on it last night. I shut it down, and this morning the computer exhibited the same infinite loop problem. The fans would whir, and some LEDs would flash, and this would happen until I turned off the power. To address this, I attempted to reset the CMOS again, and when that didn't work, I again reseated everything. I attempted to start up the computer with only the CPU, power supply, case controls, and 1 stick of ram attached, and it seemed to work - the computer at least POSTed.

So I shut the computer off with the switch on the back of the power supply, and reseated everything. But now there is absolutely no life when pressing the on button on the case. The fans don't whir, CPU doesn't run. The green LED on the mobo is on, however, but pressing the power button on the case does nothing to change the state of the computer.

What I've Tried:
I ended up unplugging everything again, and trying to boot up just the motherboard and CPU, but this didn't work. I tried reseating the GPU, RAM, power cables (both the 24 pin and the 8pin), and the power/reset/HDD LED switches, and even the fans, but nothing happened.

So that's where I am now. Any ideas on how to proceed?

Thanks in advance!!!
 

hillmanant

Distinguished
Mar 28, 2011
458
0
18,860
I would recommend Bread-boarding here is the best link to narrow it down, to me it sounds like RAM but not clear when you started with one stick and it worked then the very next restart it failed? Did you try the other stick? Start and restart with the other stick. Try this breadboardig link step by step and you should have a definitive answer what your problem component is.
http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

EDIT: Sorry this is the link I was shooting for but both will help.
http://www.tomshardware.co.uk/forum/page-262730_13_0.html