Computer Randomly Shutting Down

[Troubly]

For about a week now my computer has been spontaneously shutting down at random times. The shutdowns occur very suddenly as if the computer has lost power. There are no warnings or any popups whatsoever. I can restart the computer normally and it will seem to be perfectly normal again but then in 10-20 minutes, the computer shutdowns again. I have opened the computer to check if any of the fans are broken or if things are being overheated, but everything seems to be normal hardware-wise. I have scanned my system with Microsoft Security Essentials and Malwarebytes but have found nothing. I don't know why but the computer never turns off when I'm playing a game (just played for 3 hours with no shutdown), but when I'm on the main desktop, it'll happen every 10 minutes give or take. It also doesn't seem to turn off when I have the case open O_O, which is what I'm doing right now. I've posted this on multiple forums and a lot of people think it might have something to do with the PSU, is this correct? Why does the desktop work when I have the case open but start shutting down randomly when I close it? Is this a PSU problem or a fan cooling problem because the fans look like their working fine to me.

Manufacturer:Gateway Model:LX6810-01
Processor:Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz 2.34 GHz
Memory (RAM): 8.00 GB System
Type: 64-bit Operating System Vista
Video Card:NVIDIA GeForce GT 120

 

[o1die]

You can check both the power supply and system fans. I use a product called "perfect duster" which costs $3-5 at frys. It contains a solvent that evaporates quickly. Some folks use vacuum cleaners or other suction devices, but the canned air is safer. For a replacement power supply, newegg has some as low as $20 shipped, but I recommend a better brand such as antec or ocz which may cost $40 minimum. For the cpu heatsink, you can buy any number of thermal pastes and apply them yourself. To clean the cpu heatsink and cpu, I use either isopropyl alcohol or acetate (finger polish remover). Then apply a single drop of the thermal material to the heatsink, not the cpu as some folks recommend. spread it evenly with a single edge razor blade or old credit card. You can apply it directly to the cpu, but it's to easy to make a mess and apply too much, so placing it on the heatsink is safer. That's what the manufacturer's do.

 

[Onus]

This is most likely a PSU issue, or otherwise related to heat, since you say your system works fine with the case open.
Since companies like Gateway use bare-minimum PSUs anyway, you can't lose by replacing yours. Just make sure to get a quality model. A 380W Antec Earthwatts or 400W Corsair CX would be excellent choices. Do not be tempted by a Best Buy house-brand PSU (e.g. Dynex) as they are crap. Whatever you choose should have full range active PFC (no little voltage switch) and be 80+ certified for efficiency.

Edit: The pics of this system at geeks.com aren't clear enough, but if there's not a 120mm fan in that rear fan position, get one and install it as an exhaust. A quiet, low-speed fan will be sufficient.

 

[Troubly]

This is most likely a PSU issue, or otherwise related to heat, since you say your system works fine with the case open.
Since companies like Gateway use bare-minimum PSUs anyway, you can't lose by replacing yours. Just make sure to get a quality model. A 380W Antec Earthwatts or 400W Corsair CX would be excellent choices. Do not be tempted by a Best Buy house-brand PSU (e.g. Dynex) as they are crap. Whatever you choose should have full range active PFC (no little voltage switch) and be 80+ certified for efficiency.

Edit: The pics of this system at geeks.com aren't clear enough, but if there's not a 120mm fan in that rear fan position, get one and install it as an exhaust. A quiet, low-speed fan will be sufficient.

Thank you for the help!

 

[khubani]

Troubly,

I'd change the PSU immediately. Mine blew up an hour ago and I'm assuming I lost a $1,200 machine. Do yourself a favor, dish out the $100 for a quality PSU from Newegg, before your PSU wipes everything else out. Take it from me, you don't want to be in my position because you wanted to take a safer route. This is the safest route.

 

[Onus]

You don't need to spend $100 on a good PSU (on a new build, sure; on this, no). A 380W Earthwatts is about $40 now; if you want more head room, I think the 500W model is $80 (just got home from work; a little too lazy to look).