Some weeks ago, I decided to patch a brand new laptop, I'll share the pictures, they may help.
Before patching it like I did, the fan of this laptop, an U350 with a 1,3GHz ULV, never switched off for approx 20Â°C room temperature. The CPU was remaining at 42Â°C for a zero system load, with the fan active (noisy). I opened this U350 and noticed that this laptop had no fresh air intakes, none close to the fan.
The fan had several speeds, the fastest (like the first speed) being really loud for my needs (and ears). Some people do not complain, I think they never heard an almost quiet professional laptop. But several other do complain about "excessive fan noise"...
A few days later, I decided to drill inside, to add a fresh air intake to this case. From that point, drilling more and more into it, the CPU temp decreased by approx 10Â°C for highest system loads. I then decided to slow down also the fan speed using a common transistor/resistor circuit, to decrease the fan supply voltage.
This extra transistor itself heats a little bit up. For it's own cooling, I've mounted it pushed against the laptop's keyboard frame which is metallic. This provides an acceptable heatsink for this extra transistor.
I've lost the warranty. But I've now something quiet under my hands, even by highest system loads and room temperatures. This laptop survived over the summer, which is a good sign... I assume so.
Initially, there are no holes close to the fan. They are like forseen, but none in the box:
As internal parts and connectors are really sensitive, instead of unmounting it again, once, I just returned this laptop and started to drill more and more into it (taking care of the fan, just behind, where I drilled). This is an intermediate result, with a sticker I used to close again those holes I drilled, to make comparisons. I drilled finally more than this:
Just below it, you'll notice a Thinkpad. I made comparisons, this U350 is now almost as quiet as a r61. This is the transistor (plus a small SMD resistor) I could house under the U350 keyboard, to slow down the fan, which is now almost quiet, even at highest speeds:
If you are interested in some temperature measurements I made, you could have a look here, from page 6 (initial measurements) to page 10 (tests with those two patches, holes plus a transistor):
http://forums.lenovo.com/t5/IdeaPad-Y-U ... 811#M23311
Oops... I couldn't post links, neither pictures. You must have 3 posts before you can post URL's/Links.
I came back and posted some pictures.