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Yes, that's right. A laptop power supply.

This afternoon I was playing Minecraft on my ASUS laptop. As many Minecraft players know the game is written in Java which, on high settings, can force quite a high demand on the computers CPU. After two hours of playing my laptop popped up a notification of "[switched to] Battery Mode". Check that power supply is still in laptop, still in wall, however no green "power" LED on the power transformer. Pick up the transformer and it is insanely hot to the touch, causing the floor to be very warm underneath it. I guess there's some sort of temperature cut-out on the supply to stop it catching fire but what does one do with a flaming-hot power transformer? This has never happened to me before (unsurprisingly) and since unplugging it from the wall and laptop I have just left it to cool. I've not used it since so has it been fried? The laptop itself is running fine (using it now). I was thinking about replacing the supply anyway but is there a "best" way of cooling one down, just in case?

Granted it's probably not going to happen to many people (and now I will know to play with more breaks, and probably on my desktop instead) but still...for science?

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Get a plastic or metal bowl (maybe one from the kitchen?) that has a reasonably flat bottom, fill it with some water and put it on the top of your adapter. Glass ones or think plastic ones will not work because they conduct heat poorly. You can also get a large piece of metal foil and put it under the adapter to help both sides cool. Warning: Don't fill too much water as the bowl may topple over. – Aug 1 '11 at 17:30
I would simply put a pen under each end of the PSU. Just getting it up off the floor should help immensely. – EBGreen Aug 1 '11 at 17:32
My Dell power supply does this all the time on my alienware. I have the m11x so I can fit it on my cooling mat next to my laptop. My suggestion would be to get a laptop cooler that is larger than your laptop and then lay the adapter next to your laptop.... This might also depend on the size of your cord from adapter to the wall, I know dell sells them up to 12 feet which is nice or this purpose. – Not Kyle stop stalking me Aug 1 '11 at 18:09
A bowl of water on or near a PSU is a disaster waiting to happen (IMHO) – Linker3000 Aug 1 '11 at 18:45
Frankly, this sounds like there could be something wrong. I would consider replacing it. – KCotreau Aug 1 '11 at 19:45
up vote 3 down vote accepted

Absolutely, the best thing you can do is to allow the PSU to cool naturally, don't try to cool it quicker as doing so may cause damage (if it's not already damaged). Allow it to cool fully before attempting to use it again, and monitor your laptop and the supply when first using it in case it has been damaged.

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Just curious, as I have never heard that rapid cooling can damage equipment (other than sticking in in liquid nitrogen or something where it gets very brittle) can damage anything, can you source that? – soandos Aug 1 '11 at 17:31
My source is experience mainly, though in terms of electronic equipment Differential Cooling would be the main problem with any rapid cooling technique, which may lead to cracked solder joints and burst electrolytic capacitors amongst other things (though in this case, burst caps are likely anyway). Natural cooling of a modern power brick should reduce - though not eliminate - the chances of problems caused by Differential Cooling. – Mike Insch Aug 1 '11 at 17:36

Raise it off the floor as suggested and train a desk fan on it - and/or get a higher wattage unit.

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This is a fairly old question but I have a rather unique solution. Buy a good laptop fan just for the power brick, it won't provide so much cooling that it will cause damage but will keep it running at a reasonable temprature. I own both an ASUS ROG gaming laptop and an Alienware one as well. Both power supplies have heat issues.

Personaly I use a box fan leaning at an angle against the wall and I have made a support to hold the psu against the fan. This keeps it very cool.

The picture I attached is an older setup in which I used the power cables size to hold it on the fan! (also the psu has feet which fit in the fan notches

My Fan Setup

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If it is hot to the touch, but not hot enough to burn you (meaning, you can hold it uncomfortably), it's probably fine. Keep in mind that temperatures like 100 degrees F are considered relatively cool for electronic components. However, if it's scalding hot so that you can't touch it, it's likely that it shorted out and it needs to be REPLACED IMMEDIATELY OR FIRE!!! Less resistance, more inductance, more heat, or something along those lines...

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