Custom System shuts down randomly when in use.

Define "Shuts Down" ? Does it BSOD ? Black screen ? OR, just shut off all power ? Does it drop into Sleep mode ?

What happens when you turn it back on ? Does it just power right back up ?

What Operating system?

What are you doing on the system when it fails? Gaming ? OR, will it just crash all by itself when your Not eve Using it ?

it shuts off all power, sometimes instantly. Sometimes it drops to a black screen and i cant get it to respond, so i manually shut it down. It is running windows 7 home premium 64-bit. It happens when I am doing any task on the computer, even if im just chatting with the buddies on Teamspeak or Ventrilo.

When it drops to "black screen" do all the fans stop spinning ?

After it "shuts off instantly" does the computer reboot on it's own, or just stay off ?

What do you need to do to turn it back On ?

Let me know what motherboard you have, IF it has on-board video you could pull out the 4670 and the on-board to see if it's the video card gone bad...

Are you overclocked at all? Is your RAM timing set to the recommended or to custom numbers, either set by you or the motherboard?

I ask because I used to have these problems and the root cause was my motherboard tried to speed my RAM up too much when left on 'auto'. I would crash anywhere from just booted into Windows 7 to after playing Bad Company 2 for 30 minutes. Once I set the RAM timing to the factory recommended specs I never again experienced said crash.

Why did you remove 1 stick? Did you verify the stick was bad using Memtest+ or some other software?

Have you checked Windows Event Viewer?

When it black screens every fan is workin, even the hdd is spinning. The computer just shut down and stayed like that, though there was an instance where i would tell it to shut down, and it would restart. I just press the power button to turn it on, yet I do have to unplug and turn off psu, and reconnect sometimes. The mobo is an ASUS M4A87T-D EVO, no onboard video.

Bad RAM or even a bad CPU usually crash to a BSOD or just freeze system stays on just won't respond.

What I'm hearing so far sounds like your loosing power completely (that's why the thousand questions, sorry, each is important..)

I agree with jb6684, could be bad RAm or CPU. If you could set the RAM timing manually to the factory spec (or slower in some cases) and see if that helps.

I'm at all stock speeds, i dont know if the mobo or BIOS set the ram to higher timings....i removed one stick because when it shut down, i saw a DRAM LED blinking, so I thought i had a bad stick.

Go under your BIOS and if anything says 'auto' change it to the recommended number if applicable.

In my personally experience, a bad CPU can cause a DRAM LED to blink, so while helpful it's not 100% the root cause.

Hmmm, things are in groups:
- RAM/CPU/MB
- video
- power supply

Let's see if we can isolate a bit, but first we need to find a way to crash More often....

Download & install Prime95 & SpeedFan to watch temps
and Furmark and GPU-Z to watch temps

Now, run Furmar & GPU-Z in stability test. Keep an eye on the temps under 80--85C should be fine. Note how often it crashes.

Now, run Prime95 & Speedfan. Keep and eye on temps CPU should be under 70C. Note how often it crashes.

Does one test crash a LOT more than the other?

it's your video card....try to update the drivers....or downgrade the drivers and see what happens

In Furmark, there is only Burn-in, 1080p,720p, and no preset benchmarks.

User Version 1.8.2 of FurMark :

http://downloads.guru3d.com/FurMark-1.8.2-download-2523...

Set Run Mode to Stability

Set Window Parms to FullScreen

Leave Standard Sizes to 1280x1024

Press GO...

I ran both stress tests. The Furmark tests ran flawlessly, only climbing to about 62 degrees Celsius in temperature. After about 3minutes in Prime95, the system crashed. After booting and welcomed onto the desktop, the system froze. Another manual shutdown...so many manual shutdowns CANNOT be good for the system...is the issue the CPU? Because the box it came in is gone...so RMA through Newegg is gonna be tough if not impossible

OK

Hmmm, things are in groups:
- RAM/CPU/MB
- video
- power supply


So, if FurMark is almost ALL GPU load. It runs great, so, your Video Card should be good.... (and, since GPU draws a lot of power, power supply is likely good too...)

That leaves us with RAM/CPU/MB...
- you can change settings in Prime95 to "Small FFT not much RAM" see if this is more stable...
- you can run with ONLY 1 thread to see if that is more stable.....

I would guess try another power supply   ! ask a good friend to let you test your computer parts in his her computer, and do it one by one an then u will know what is the faulty one when his her computer fails. I am just trying to give another options so your rig wont have to be turned off in an anormal way.

good luck !

Ran for1 hour in Small FFT mode on 1 thread, flawless. temperatures didnt creep above 35 celsius.

I recently had a similar issue. Turned out to be a driver problem with the Realtek onboard audio. Purchased a 20 dollar ASUS XOnar DG sound card and everything is peachy 

It wouldn't hurt to disable your video card audio as that gave me problems, but not my main issue. Do you have a friend with a compatible motherboard?

As I am only 14 years old, not many people can build a computer...most of my friends have a pre-built with a junk mobo. So no testing  

I understand, I was just lucky enough to have a group of people that were all building systems at the same time, but we were a little older then. Try the suggestions and keep letting us know how it goes.

Okay. Seems like it's CPU or RAM. Leave the same setting and increase the thread count to 2. Your right to keep an eye on temps.

If you find you can increase your thread count step by step back up to 4 and remain stable, then its your RAM that is the failure.....

If you find increasing the thread count above 1 causes failures then its your CPU that is bad....

I increased the threads up to 4, where there was a few crashes..

Ok, return to one (1) thread only. Run for an few HOURS....

IF No crashes at all, try the other settings on PRIME 95, those that use more RAM..... run a few hours each.

IF everything is solid for hours on one (1) CPU, at all three settings of Prime95, then I believe it would be a BAD CPU for sure...

Did you ever find the soulution? I am having the same problem.
Ultra 650 LSX
ASUS M4A87TD EVO
Corair CMX4GX3M2A1600 4GB
Windows 7 Home Premium
WD5002aalx Caviar Black
Sapphire 100283-31 Radeon HD 5770
AMD PhenomII X4 955 black edition
LiteOn Ihas424-98
Please let me know Reg

Not sure if first meesage went throgh- I am having the same problem- did you ever find an answer?
Ultra 650LSX
ASUS M4A87TD EVO
Corsair CMX4GX3M2A1600C9 4GB
Widows 7 Home Premium
WD 5002aalx Caviar Black
Sapphire 100283-31 Radeon HD 5770
AMD Phenom II X4 955 Black
Light-On Ihas424-98
If you soved your problem please let me know what it was. Thanks Reg

i had the same problem couple of months ago....i tried everything...replaced the ram, cpu, psu, gpu....except the mobo...then i replaced the mobo and it worked fine...i never saw the problem again...i dnt knw the reason bt changing my mobo worked....i have phenom ii x2 with gigabyte 880gm ud2h...
my system shut down randomly, and did not start for 15 minutes or so...i had to turn off the power switch on the psu to start again....

here is the thread which i started, it might prove to be of some help
http://www.tomshardware.com/forum/forum2.php?config=tom...