[GH-ISSUE #1402] Would need help to get fan control for HP Pavilion tx1000 working #1209

New issue

Closed

opened 2026-02-26 00:34:40 +03:00 by kerem · 2 comments

kerem commented

2026-02-26 00:34:40 +03:00

Owner

Originally created by @freakedenough on GitHub (Aug 17, 2024).
Original GitHub issue: https://github.com/hirschmann/nbfc/issues/1402

I already found out via ec probe monitor, that 0xAC and writing 05 up to 15 changes the fan speed (10 steps, 0 to 100%). For a second only. So i have to switch to manual control.
Opening the device, I identified a controller chip labeled "ene KB3920QF-BO" and if I'm correct, this would be the datasheet that describes fan controlling from page 43 onwards. KB3920_ENE.pdf

But it uses different address names than NFC, and since I am not that deep into hex numbers, address spaces, etc. I am about to give up. I tried to write 00 to random addresses marked in red (by ecprobe dump)
Setting 0x40 to 00, i can no longer spin up the fan writing 15 to 0xAC. And also the system stops adjusting the speed automatically too. Writing 0x40 back to its inital value A3 (163) I can control the fan again and also the system starts controlling it again automatically. I am slighly confused.

Here is my DSDT dump (I found VFAN and FANC as only matches for FAN in there) and ec-probe dump. I hope someone more andanced than I will find the key to unlock the fan control.

dsdt.json

                Field (ERAM, ByteAcc, Lock, Preserve)
                {
                    FANC,   1, 
                    Offset (0x42), 
                    VFAN,   1, 
                    Offset (0x4E), ```

Originally created by @freakedenough on GitHub (Aug 17, 2024). Original GitHub issue: https://github.com/hirschmann/nbfc/issues/1402 I already found out via ec probe monitor, that 0xAC and writing 05 up to 15 changes the fan speed (10 steps, 0 to 100%). For a second only. So i have to switch to manual control. Opening the device, I identified a controller chip labeled "ene KB3920QF-BO" and if I'm correct, this would be the datasheet that describes fan controlling from page 43 onwards. [KB3920_ENE.pdf](https://github.com/user-attachments/files/16644879/KB3920_ENE.pdf) But it uses different address names than NFC, and since I am not that deep into hex numbers, address spaces, etc. I am about to give up. I tried to write 00 to random addresses marked in red (by ecprobe dump) Setting 0x40 to 00, i can no longer spin up the fan writing 15 to 0xAC. And also the system stops adjusting the speed automatically too. Writing 0x40 back to its inital value A3 (163) I can control the fan again and also the system starts controlling it again automatically. I am slighly confused. Here is my DSDT dump (I found VFAN and FANC as only matches for FAN in there) and ec-probe dump. I hope someone more andanced than I will find the key to unlock the fan control. ![Aufzeichnen](https://github.com/user-attachments/assets/c8c2b7dc-fa4e-4c32-b70b-0a26b0484d06) [dsdt.json](https://github.com/user-attachments/files/16645006/dsdt.json) ``` OperationRegion (ERAM, EmbeddedControl, 0x00, 0xFF) Field (ERAM, ByteAcc, Lock, Preserve) { FANC, 1, Offset (0x42), VFAN, 1, Offset (0x4E), ```

kerem

2026-02-26 00:34:40 +03:00

closed this issue
added the
Stale
label

kerem commented

2026-02-26 00:34:40 +03:00

Author

Owner

@freakedenough commented on GitHub (Aug 17, 2024):

I mean, I could at least now create a 100% bat file that executes ec-probe twice:
ec-probe.exe write 0xAC 15
ec-probe.exe write 0x40 00

Thats fast enough to keep it at 100% before it would be automatically reset to whatever value.
Another bat file to reset FAN back to automatic..

ec-probe.exe write 0x40 163

@freakedenough commented on GitHub (Aug 17, 2024): I mean, I could at least now create a 100% bat file that executes ec-probe twice: ec-probe.exe write 0xAC 15 ec-probe.exe write 0x40 00 Thats fast enough to keep it at 100% before it would be automatically reset to whatever value. Another bat file to reset FAN back to automatic.. ec-probe.exe write 0x40 163

kerem commented

2026-02-26 00:34:40 +03:00

Author

Owner

@github-actions[bot] commented on GitHub (Feb 15, 2025):

This issue is stale because it has been open more than 180 days with no activity. If nobody comments within 7 days, this issue will be closed

@github-actions[bot] commented on GitHub (Feb 15, 2025): This issue is stale because it has been open more than 180 days with no activity. If nobody comments within 7 days, this issue will be closed