My laptop's CPU fan is suddenly acting very bizarre, and I am at a loss for what to do so I am asking for some help. Specifically, the fan is not even starting to spin until the CPU reaches 60 degrees Celsius (checked through HWmonitor). Once it is on, however, it properly stays on even when the CPU gets back to idle temps around 38 Celsius. Before, the fan was simply starting with the computer and staying on like normal. I've checked this for consistency both by allowing cold boots to ramp up temperature to 60 Celsius (the slow climb also causing the laptop to become unreasonably warm near the heatsink), and also running Prime95 immediately to kickstart the fan (this works every time). The fan seems to be stationary when turning the computer on from either sleep or shutdown. The fan will start at POST very briefly, and then stop completely. I've checked the BIOS for a SmartFan setting but haven't found any. I've opened the case to check for dust or debris and have not found anything (I applied some canned air to the area just in case). The laptop is a Lenovo ThinkPad Edge E430 and the CPU is an Intel Core i5 3210m @ 2.5 GHz. Any advice would really be appreciated.

bump

Ever thought of controlling the fan manually?
Like using the programm speedfan or something similar.
You seem to have pretty much done everything you could.

Is it actually a problem though? Sounds like the fan is just running when needed...

Check Power Saving setting in the BIOS and/or Control Panel.

Edit to add: Sometimes when I want to isolate whether a hardware of software issue, I temporarily disable them completely to see if I can effect the change I desire that way.

I forgot to mention that I came across this product in my search and gave it a shot. Unfortunately, it was to no avail, as the program seemed to crash regularly for me. I've actually gotten this same answer elsewhere, but here's the issue as I see it: until the CPU climbs up to 60C, the fan is completely off. If I just use the laptop as normal to say, browse the web or write or whatever, it's a rather slow climb to 60C. That means my CPU temp is hanging from 40-50C for a long time without any sort of ventilation push. The heatsink under the keyboard gets extremely hot and the whole laptop feels like it's burning. But until that CPU reads 60, the fan stays off. Actually good general advice, thank you.

I adjusted my power plan to active system cooling, I went ahead and updated the BIOS so I will check it again to see if I can access some sort of fan system.

Could be a fan issue: are you a smoker or do you have people who smoke heavily in your house? Also, pet fur and dust can clog cpu fans in laptops. My general advice for you would be to get the laptop to a service center for particular brand you're using so they can check it up in case the problem lies in motherboard thermal sensors, if thermal program someone suggested crashes on your system it could be that some of the sensors are dead. It could explain your current problems.

Hmm... can you connect your fan to a connector WITHOUT fan speed control (3 pin)?

I looked at page 129 in the manual from Lenovo for the laptop, and it indicates there is a 'Power Manager" feature, but does little more than mention it.

It seems like this might be a promising area to check; looking for additional nfo now.

Edit, formatting.

Edit to add: link to feature and docs.

http://support.lenovo.com/en_US/detail.page?LegacyDocID=MIGR-70601

No smokers here but I do have a cat. I did open the laptop and use some canned air, making sure that the fan was spinning freely. It appeared fine but you could be onto something about the sensors. Power Manager is simply their power plan software that lets you make custom settings for battery use. I've had experience with similar programs on other laptops and I found the Lenovo one to be lacking in comparison. I uninstalled it long before this issue appeared. Nothing on the current board, and I unfortunately don't have any spare mobos to try it on at the moment.

Please ignore link, above, then :-)