Severe overheating problem even when idle.

davemrt21

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Jan 11, 2008
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I have an Asus 17" notebook (Model G73SW-XN2) with an nVidia GTX 460M graphics chip on it. I am running Windows 7 64-bit.

I recently developed a problem where the fans became very noisy and started making scratching sounds. Sometimes a fan will go off spontaneously, but if I tap the back of the computer in the region of the fan, it will turn back on. I understand that I probably have defective fans and I am trying to build up confidence to open the computer and take a look inside. I have never done it before so I am worried. The computer is out of warranty.

However, something strange happened today. The computer screen turned dark and the computer shut itself off while I was working. I had no particular load on the CPU/GPU other than a few browser windows open, and a movie playing on VLC in one corner of the screen. For a while, the computer wouldn't turn on, but after about 5 minutes it came on when I pressed the power button repeatedly.

I noticed immediately that the graphics looked funky, like they were low resolution, but they seemed to correct themselves after a couple of minutes. I immediately started speedfan to monitor temperatures, and I noticed the GPU was at 78 C, the CPU cores at 45-55 C. I could not hear any fan sounds so I am guessing the fans didn't come on.

Like I said, I understand the fans are defective and I need to open the machine and examine them. But the thing I don't understand and the reason I'm posting is why my GPU should be at 78 C.(even without a fan) when there is absolutely no load on it other than just Windows. All I had open was a browser window, Speedfan itself, and Task Manager. Windows was literally idling, not doing anything at all other than displaying the desktop and a couple windows. No video playing, no games, no flash ads in the browsers, absolutely nothing but some text.

Why is my GPU so active when it's barely being used that its temperature rises to 78 C? Even in the absence of fans, should it really be that hot when it's not doing anything but draw the Windows desktop? Is there some sort of process that might be running in the background that might be using the GPU without my knowing it?

Any help is much appreciated, as well as advice on how to deal with the fans and overheating problem.
 

Geekwad

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Sep 25, 2015
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This all sounds like thermal throttling.....and you're right, your destiny is to open the computer up and fix the fans (unless you pay someone else to do it) :)

You can start by just opening the back up and spraying a good load of canned air into....all over, really, but concentrate on the fans. Go at it at least twice. This may help, or not at all. When you're in there though, check to see just how difficult it is to get to the fans. Sometime the designers make easy (as it is a wearable item), and it may just be a few screws and a small, easy to get to, connection to the mobo for power.

If that looks well beyond you though, you can get a laptop cooler to see if that helps, and then try to find somewhere to get them replaced.

In the meantime, check your Windows power plan and make sure it's in 'power saving' mode to take it as easy as possible on your CPU/GPU.....
 

davemrt21

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Jan 11, 2008
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I checked some YouTube videos earlier about opening my computer to access the fans, and found out that it's a complicated process that involves going in through the front, taking out the keyboard, the faceplate (which is also a heatsink) and a bunch of other stuff. This is why I am hesitant to open it. It's not a simple matter of removing a few screws. The video also shows that the fans are buried pretty deep inside the case and connected to the vents through ducts, and the video guy said that for this reason blowing canned air from the outside is of no help.

I expect that regardless of the difficulties, I will have to open the case and examine the fans because there is obviously a fan problem. I am a poor student so I'd rather do it myself than take it to a repair shop.

But that still doesn't in my mind answer why the GPU should be so hot when the notebook is idling, even without a fan. I have the power options set to battery mode, meaning it throttles the CPU between 5% and 70% depending on load. But the power options have nothing to control the GPU throttling, and neither does the nVidia driver.

So why should my GPU be at 78 C when I'm not doing any 3D task, when I have nothing open other than a couple browser windows (with text only, no video, no flash, nothing that strains a GPU), plus a speedfan temperature graph.