laptop - Can thermal paste damage CPU and video card some time after applying?
2014-04
Javidan
Three weeks ago, I disassembled my notebook to clean its heat sink. I re-applied thermal paste and re-assembled it. It worked well, until about three weeks when it hard shut down while I was working with it. When I tried to turn it on again, it only got as far as the desktop before shutting off. After a day, the power button did nothing at all.
Service said that there was a problem with the video card being unsoldered and soldered a new one in, but it has stopped booting again. Now I think that I may have applied applied more thermal compound than usual and that it somehow damaged my CPU or video card.
What did I do wrong?
Wolves
Is it silver-based thermal paste? If so, its not particularly conductive to electricity, but it does have some capacitance. If it is in contact with any of the connections on the CPU, motherboard, RAM, or video card, it could potentially cause the problems you are encountering. It can essentially slow down data flow, which can generate errors causing the system to shut down, particularly if it gets on the RAM.
If there is any extra anywhere in your system, it would be a good idea to try to remove it carefully.
RichieACC
I was told many years ago to do this by someone who at the time knew more than I did. The CPU was a celeron in the Pentium 2 era. It ran cooler with the toothpaste between the chip and the heatsink than what it did with nothing between.
Has anyone else ever heard of or tried this? What were the results?
Yar
This is the standard "saran-wrap-in-place-of-condom" question. While some toothpastes may provide the correct type of thermal conductivity, "toothpaste" is too big a category to answer the question accurately. Worse, unless you want to make it a fun science project, nobody is going to be testing different types of toothpastes for thermal conductivity.
That said, the answer is probably "yes." Toothpaste is definitely better than nothing, because air (i.e., nothing) is a terrible heat conductor. That said, there are other properties to consider. From Wikipedia
- How well it fills the gaps and conforms to the component's uneven surfaces and the heat sink
- How well it adheres to those surfaces
- How well it maintains its consistency over the required temperature range
- How well it resists drying out or flaking over time
- How well it insulates electrically
- Whether it degrades with oxidation or breaks down over time
I think that toothpaste might work for the thermal part, but you might have other problems in the short- or long-run.
On A Different Note: That said, if you need to stick a note to the wall, you can definitely use chewing gum (after chewing a bit). Sometimes it's hard to get off when your lease is over, though :)
pavium
It might be better than nothing, but unless toothpaste has unsuspected thermal conductivity, I'd say it's a bad idea.
You also have to consider what the ingredients of the toothpaste might do in contact with your CPU. I suspect it would be pretty conductive in an electrical sense. You don't want electrical conductivity.
Better get some real thermal paste. It's more expensive than toothpaste, but worth it.
hyperslug
I remember hearing about this at Dan's Data a while back, and he went back and forth with Arctic Silver's Nevin on the issue.
I think the basic idea was that toothpaste will dry up faster than true thermal paste, perhaps leaving you a lot worse off than if there was nothing at all. So, if you like removing your heatsink as much as I do, then no, it's not ok.
user26528
If it ran cooler why isn't using toothpaste more common? Perhaps the person who told you this was a dentist and had a bias opinion. If you want to keep your CPU safe and cool for a long time, use thermal paste. If you want to protect it from cavities and gingivitis, by all means, Colgate Total is the best option.
systemBuilder
I've been using a rebuild with toothpaste on my Thinkpad T42 for about 3 years, with no problems. These laptops, however, are known for running cooler than most thinkpads, to begin with, and we don't play very many 3-D games on those ATI 9600's, so the load on the toothpaste is not very high. If you are worried about the paste drying out, just use A LOT. The only part that will dry out is the stuff on the edges of the CPU, and if you are generous with the paste, there should continue to be a large amount in the middle of the CPU that is thoroughly wet ... or use 25% vaseline and 75% paste... or 25% grease and 75% paste. Grease is basically oil & soap, to keep the oil from drying out.
Remember, toothpaste drops the temperature by 20 degrees, even after 12-hours of burn-in, and arctic silver 5 drops it by 29 degrees at most. So toothpaste gets you 69% to cooling nirvana, even after the dry-out period.
Yossi
I put tooth paste between the heat sink and the CPU with the Colgate Total Advanced... It works like a champ!
If there will be an issue in the future, the PC knows how to protect itself, and it shut it off.
I used it on my 5 years old computer that I didn't care too much.
So far, again, it works great. I spread the paste with an old credit card, and cleaned the old paste with Lysol before I applied the tooth paste.