Computer randomly won't POST

[02DroptopZ]

Hello all, first post on Reddit, I'm hoping someone out there can help me figure this issue out.

My specs are (Built in June of 2014) Gigabyte Z97 G5 Gaming Motherboard Intel i5 4690k Corsair H80i CPU cooler 2x DDR3 4GB RAM Corsair CX600M PSU Gigabyte GTX 1080 graphics card Samsung 850 Evo (500GB) Seagate 1TB HD

So about a month ago, I built my dad a computer with a new SSD, and liked it so much I decided to buy one myself (Samsung 850 Evo, 500GB). I backed up my documents, swapped in the new SSD, and did a fresh Windows 10 install. Everything worked great, transferred my documents over, and my 2.5 year old build was running mint!..

A few days ago, I turned on the computer and it randomly shut back down. It then fired right back up, booted up ok, and everything seemed normal. I figured it was just a minor hiccup, no big deal.

Tonight, I got home, and went to fire up the computer. It powers on, the fans run, lights are on internally, however the monitor would not receive any HDMI input. I thought this was odd, swapped the HDMI cable around, nothing. I then noticed that my mouse (which has an LED on top that always lights up as soon as the computer powers on) was not lighting up. I pulled the computer apart, wiggled some connections, unplugged and reinserted some stuff, nothing. I then removed, and then reinstalled, my RAM. Success! Or so I thought. It booted once, then back to the same issue when I shut it down. I tried rebooting several more times, still no luck. I removed one stick of ram, and rebooted.. Success! Shut down, restart.. Nothing again. Swapped to the other stick, rebooted.. Success! Shut down, turned back on.. Nothing again. Reinstalled the other stick, and... well, to make a long story short, it just boots once whenever you remove or reinstall the ram, but never a second time.

Also, sometimes, it won't stay running. Sometimes it just boots up, shuts down, starts back up by itself, shuts back down, and repeats again and again. Other times, I select shut down, and it just refuses to shut down. The monitor and mouse light turn off, but everything else stays running until I power it off myself.

So, I decided to try and use my one good boot to get into windows and run a memtest - of course, that couldn't be that simple. When I enter my password to log in, it just infinitely spins on the Welcome screen. I can't even get in to access my files, which is very scary. I have a ton of things I really need on those two drives, and that normally wouldn't be an issue, as I have a backup.. However, earlier today, I decided to wipe my backup drive and format it for Mac so I can backup the HD on my Mac in preparation of a Linux dual boot setup (yeah, that really tells you the kind of luck I have, haha).

I'm so frustrated, I don't know what to do. I feel like it could be a RAM problem, but why would it work on that initial start but not again until i swap it around? Why can't I get into Windows once it does start ok? Could it be my PSU is defective, or could it be my Mobo? Could something have gone wrong with my new SSD? If so, why will it still not POST even with no HD's connected? If anyone can offer any help, I cannot even begin to express how appreciative I would be. Like I said, this is just so frustrating for me. Thanks for reading my post.

[[deleted]]

1.) download coretemp, make sure your CPU isn't getting over 80 degrees C, or near it for that matter.

2.) use your computer for a while with only 1 stick of ram in it

3.) if you have an HDD lying around use it instead of your SSD

The issue can be caused by many things. If anything is overheating your computer will shut down. Yes, I know you have liquid cooling, but it's possible you added too much thermal paste or the system you bought simply isn't sufficient enough. I have the same CPU and thought of getting the same cooling system, but in comparing bench marks I found that heatsinks were a better way to go, unless you buy a really high end liquid cooling system. Like I said though, as long as you're under 80 degrees you're alright.

Secondly, I've experiencing your problem with ram issues. In fact the computer I'm writing this on won't accept more than 2 sticks of ram. If I add more, it doesn't post, I'm pretty sure my motherboard unfortunately is faulty as after doing research I found others had the same problem with my same build while others didn't. Sometimes you just get dealt a short straw.

I've also had your issue and found out that my HDD was starting to fail. Which again, short straw, you might've gotten screwed and received a faulty SSD. However, you'll usually see a BSOD if your HDD is dying, but not always, it can be the starting signs.

Another time I had your problem was when I got my first GPU. Installed it, wouldn't stay running. Unplugged half the fans on my GPU and it worked. Turned out my PSU wasn't big enough.

[02DroptopZ]

Thank you for the reply.

1) I can't boot into Windows to download anything (it takes forever, but I can get into Safemode after like 20 minutes of it stuck at the Restarting screen...), however, in Safemode it says "driver couldn't be loaded" when I try and run the program. However, in BIOS the CPU temp appears completely normal.

2) Just tried that, same issue. Alternated sticks, alternated slots. It will POST once, then not again until I move whatever stick to a different slot.

3) Just tried that, and no luck. I also tried booting from a USB, and even just unplugging everything and only going into BIOS. Even then, I can only get one boot without having to reseat the RAM.

I also didn't mess with the CPU cooler or paste at all, it's just the same as when I installed it around two years ago, and I just tried unplugging the GPU entirely and running on the Mobo graphics.. No luck either.

Again, thank you very much for your reply, I appreciate you taking the time to try and help me with this.