-
×InformationWindows update impacting certain printer icons and names. Microsoft is working on a solution.
Click here to learn moreInformationNeed Windows 11 help?Check documents on compatibility, FAQs, upgrade information and available fixes.
Windows 11 Support Center.
-
×InformationWindows update impacting certain printer icons and names. Microsoft is working on a solution.
Click here to learn moreInformationNeed Windows 11 help?Check documents on compatibility, FAQs, upgrade information and available fixes.
Windows 11 Support Center.
- HP Community
- Archived Topics
- Notebooks Archive
- Re: Fan will not go to full speed on ProBook 4720s
Create an account on the HP Community to personalize your profile and ask a question
08-25-2012 04:50 PM
to: erhart-jir
there is a temporary workaround. do it only at YOUR OWN RISK.
this procedure only works on ProBook 4720s F.20 bios. DO NOT ATTEMPT THIS METHOD ON OTHER MODELS!!!
it works only when the laptop is on AC POWER. download "read and write utility" from http://rweverything.phpnet.us/. run the program then click the EC icon (embedded controller). in the embedded controller window that opens you will see a matrix of 16x16=256 numbers choose the one in column marked "05" and row "D0". that number has an offset address of 213(in dec) and probably a value of 1E.
(if you didn't find it don't attempt to change a random number, its risky)
change the value to something from 0 to 70 (don't go over 7F) and the fan will speed up to the desired value.
also do not change any other values - risk of hardware damage
the procedure must be repeated on every startup
this procedure only works on ProBook 4720s F.20 bios. on other models the offset is different so do not attempt this method !!!
do it at your own risk only
the core of the problem probably lies in the bad DSDT table (that came with the bios), but i guess you would need an expert to fix it.
if you need more help you can leave a post
08-29-2012 01:41 PM - edited 08-29-2012 01:43 PM
to: fanerror
Thank you for your reply, it isn't the type of solution I was wondering to receive, but at least I know where to search further and I can use the computer without having to worry about the temperatures.
If anyone knew a way, how to solve this problem OS independently, like somehow fixing the current BIOS, please post it here. I'm sure it would help more people than just me.
02-05-2013 01:14 PM
to: barbahann:
A not so elegant solution would be to change and keep changing the value at 06 D0 (right next to 05 D0). Something keeps writing into this adress, so you would have to write in it faster (~every second). You can use the command window in RW to wtire a simple script that does just that.
in the command window you can use this script line to write the value of 0x50 on every 1000ms ( = 1 second)
LOOP{0, DELAY 1000; wec 214 0x50}
this solution doesnt work very well and the fan's speed will wary a bit.
the only permanent solution is for someone to fix the bios. (or maybe the problem lies in the ACPI tables)
03-05-2013 12:38 PM
Your notebook is an Enterprise/Business model. I would recommend posting this in the HP Enterprise Support Forums for better coverage.
You can access the enterprise support forums at the following link.
04-20-2013 12:01 PM - edited 04-20-2013 12:13 PM
Didn't find what you were looking for? Ask the community