cpu fan not working on battery.

[fst]

i am using hp elitebook 2540p with windows 7 64 bit operating sytem.my problem is when i am working on battery power cpu fan not working my notebook getting too much heat.when it connecting power cable it is working smoothly and maintain it cooling system.after i find out this issue bios version updated to new one available in hp wesite.still that problem is not solved.any one can help me how to fix this problem.

FST

[Huffer]

You will lose some battery life, but if you dig deep into the advanced power settings you can set up "active cooling" while on battery, as in this tutorial:

http://www.7tutorials.com/how-tweak-advanced-settings-power-plan-windows-7

It is the system cooling policy and you can set it separately for AC power and battery. The default on battery is passive, I believe.

If this is the "Answer", please click "Accept as Solution" so it can help others.

[Pikolo]

Hi Dean,

I have the same problem on Pro Book 4720s.  When the note is on AC power fan works, when is on battery it does not till there is 100 or more degrees Celzius in CPU. Then it starts slowly, few turns and stop.

OS is Windows 7.

I put some peace of SW which I am able to control the fan and same problem - on AC works and I am able also to define speed of fan at points of temperature.

On battery also this solution doesn't work.

On windows I already take high performance plan - cooling option on active under battery - doesn't work. Also HP Power adjustment doesn't work.

I already search a lot on this problem and there is possibility that BIOS DSDT tables are wrong - BIOS is the last F.21

What bothers me is why fan does not spin under battery while under AC works ok.

If you have any idea or you can get some internal HP info I would appriciate.

BR,

Grega

[wojtek76]

hi.did you fix it ever,I have the same problem?

[Pikolo]

Unfortunatelly no. Still same issue. It seems that the bios is controling this part and can be override do some reason. Now I'm running it only on AC which mean I lost functionality of notebook :(. I will look forward and also hope that some HP technical guru will still see this post and come out with solution :).

[wojtek76]

Yes,I think the same this is problem with bios

[Ultraspark]

Hi, I had the same problem on my EliteBook 2540p with Windows 8.1 Ent x64 Upd 1, (BIOS F50) but I found that enabling the ME (Ctrl+P) have solved my problem. I think it is a bug in the latest F50 Firmware for EliteBook 2540p. Hope to solve it fast.

Best Regards!

[salva756]

this is very very important, is the first time i hear a possible solution, i have bought 4 motherboards of hp 2540p in ebay, and all have the same problem on windows 8-1 64 bits.. fan only work with AC power, with battery fan doesn't spin. Please describe what have done you?. i don´t know what is ---ME enabling-- what have i do to? thank you so much...

salva

[Ultraspark]

Yes, this is for sure a bios bug guys. First of all, assure that you have the lastest F50 BIOS and Latest ME Firmware.

Most of users don't use AMT (Active Management Technology) and disable unused devices/features in bios. For example, I have disabled the MODEM, FINGERPRINT, SMART CARD, because i dont use these devices and features. Actually, by default the Virtualization is disabled, but you can enable it to use for some virtual machines. 32bit ones will work without virtualization enabled, however, you'll not be able to run 64 bit ones without VTx. So, my BIOS is configured to disable listed above devices and have Enabled Virtualization. Also disabled all that HP QuickLook, and QuickWeb. 

Access the AMT Option and first check the Unconfigure AMT at next boot. Then save and reboot. After that, access the bios again and go to AMT and have Verbose and CTRL+P option enabled. Save and reboot again. In the POST process you will see a promt to press CTRL+P. Press it asap. The default password is "admin". You will be promted to change for another one. Go to General Settings and check if the ME State is enabled or not. Select ENABLE, press ENTER, then press ESC and boot your OS. Check if FAN is working. It should work. In Power Options from Control Panel in the processor power management the fan under battery should be passive, not active. Only in AC should be Active.

If everything is OK, reboot, and go to bios and go to that AMT option and uncheck the Verbose and Ctrl+P to get ride of any messages about AMT that you don't use. That's it. 2540p is really very good notebook. Mine is top configuration and have an Intel x18M SSD and it is really fast. Buy an SSD for it will serve you 4 more years 🙂

[Pikolo]

ablHi Ultraspark, it seems that also some option is available on some comp and others not. I check what you wrote and in my Bios (last one F.50) does not have any AMT option available. Should be this separate tab or is somwhere inside hidden.

Probook 4720s which I own is also very good note but this thing with fan and battery is really rediculous.

Br,