GPU Running at almost double temp after applying AS5?

[ryangarfield]

My laptop fan was making very load noises, so I decided to check the temperatures of my CPU's to see if they were running too hot which would make my fan run so hard. Core Temp said the two cores of my Turion 64 were running normal at around 35-40C, but another program said my GPU was running hot at about 50-52 degrees doing light internet. So I decided that maybe the thermal compound was the problem. This was my first time ever doing this, so I took my laptop apart got to the CPU/GPU and put AS5 on them both. My CPU cores now run at about 28-35 so that seemed to be a success, but my GPU now runs between 90-100 when playing a simple video in VLC. So I'm not sure what I did wrong. THe only thing that I can think of is that the GPU prior to my medling had a thermal pad on it rather than any kind of paste and this pad is about 1mm thick, so maybe the GPU is no longer connecting to the heatsink? I still have the thermal pad, it tore in half but should I put it back on over top of the AS5 or just wipe off the AS5 and put the pad back on?

[TBoneit]

Put that pad back now and order the right replacement pad.

Personally I'd stop using it if the GPU is running that hot, especially if it is a Nvidia GPU.

There are a lot of laptops out there that have failed/failing/about to fail Nvidia GPUs due to problems with the solder on the BGA attachment to the motherboard. It was especially prevalent on HP laptops with Nvidia GPUs and AMD CPUs due to the higher temperatures.

Toshiba service manuals indicate to replace the pad for example and what CPU heatsink compound. If you have to replace the motherboard under warranty those items can be ordered as part of the warranty so obviously Toshiba considers them important to change and use.

Good Luck.

[redwudz]

I would probably agree about putting back in a stock thermal pad, but I'm wondering why such a change in temperature?

Maybe the heatsink is badly warped or you used too little or too much thermal compound? I use a piece of plate glass to check for warpage. Did you throughly clean off both surfaces with something like Isopropyl alcohol 99%? Are you sure the HS is seated properly? Maybe the thicker(?) pad is also a spacer to ensure proper contact and tension of the cooler against the chip surface?

In most cases, if the thermal pad isn't hardened or dried out, it would function to specifications. You 'might' get some efficiency improvement with AS5, but I use non-metallic thermal compounds these days as you don't want the AS5 to get on any circuit leads.

50C isn't unusual for a GPU. Most of my PC video card GPUs run at about that temp, even with sufficient cooling. They seem be less efficient using power than the rest of the computer. But ~100C is bad.

EDIT: I definitely wouldn't use the compound and the thermal pad. That could cause new problems.

[Bjs]

Next time you should include the make and model of the laptop which helps with diagnosis of the symptoms.

As mentioned before ... put that pad back in for the gpu ... AS5 is not a gap filler.

[ryangarfield]

So I've now put the thermal pad back in place and its gone back down to around 60C. looking at the heatsink there wasn't any AS5 on it so it obviously wasn't making contact. I apologize for not mentioning the model sooner its a Compaq Presario V6310US. Looking on ebay for replacement pads I noticed several sellers listing little copper spacers for my model and a few others in the same series. I guess this piece eliminates the gap between the heatsink and GPU. Would it be worth purchasing one of these?

[redwudz]

That's up to you. I'm guessing those spacers allow you to use regular thermal compound, but they may just be shims for the thermal pad. depends if they are about as thick as the pad. If you have a few extra $$ to spend, you could get both and try the spacer and thermal compound first. Or the safer way is to just put in a new pad by itself. As mentioned, 50C is not really hot for a GPU.