Lenovo Legion Pro 7 16IRX9H (i9-14900HX / RTX 4090)
serial Number: PF4Z0VV5
Machine: 83DE000AUS
Looking for help repairing a suspected corrupted BIOS/NVRAM on a Lenovo Legion Pro 7 16IRX9H (i9-14900HX / RTX 4090).
Ive relied heavily on ChatGPT to help diagnose this so apologies for the long-winded commentary.
Background:
Got laptop used and the GPU was not being detected by the OS.
Standard driver install failed (Nvidia failed to find compatible device error) and speakers do not work (External sound does).
Successfully installed drivers via “Have disk” method and card is now detected, however:
GPU works - But peaks at ~80W power limit (should be ~175W) - limits confirmed in HWInfo
GPU-Z shows Subvendor = Undefined
Internal speakers non-functional (Windows shows playback activity but no output)
External display + G-SYNC working
External audio working
What I’ve tried:
Multiple NVIDIA driver reinstalls
Flashed VBIOS via NVFLASH
Lenovo Vantage + official BIOS updates (N2CN28WW → downgrade to N2CN26WW → back to N2CN28WW)
BIOS reset / defaults
Crisis BIOS recovery attempts (Fn+R)
No change in behavior
Current state:
System boots and is stable
GPU detected and functional but power limited (Perfcap = PWR, ~80W max)
Audio codec enumerates but internal speakers dead
SPI work:
Dumped BIOS via CH341A (GD25B128E main chip)
Verified dump integrity
16MB size
Multiple reads match (bit-for-bit identical)
No write performed yet
Note there is a second, 8MB chip i can upload too if needed.
Listen, made this account to hopefully help you or someone else out. These EXACT same symptoms happened to me earlier, i spent 6 hours diagnosing and hurting my brain over it. Yesterday the laptop was completely fine, after a restart it started doing this. Well… i fixed it. Same issues as you, could not for the life of me get the 4090 to respond or get identified and my speakers were not working even thought they showed that they were. Even went as far as a fresh windows install.
Exact steps i took in order (Don’t judge):
-take back cover off
-remove any grime/dust on the board
-disconnect and remove the battery (idk why i removed it) needed to remove the left ssd (with battery side closest to you orientation)
-disconnected the left speaker, i didn’t disconnect the right one for some reason
-disconnected CMOS battery and held down the power button for a minute,
went to smoke a cig then came back and put it all together
god speed friends
haven’t tested the 4090 but if the power limit is off or unstable i’ll come back on here
edit: for some reason it’s only doing it when i restart the system while it’s plugged in, if i restart it on battery all is well
Appreciate the response my man! I ended up flashing the bios using one provided by another forum and it made no difference. Also tested what you suggested and unfortunately it also did not work for me.
Since posting this i have been able to get the GPU to work at full power - though i still have to force driver install.
The speakers and microphone on the other hand are refusing to work no matter what i do. I would really love to get to the root cause of this to understand what on earth is going on.
i’d love to as well, i had to restart earlier and it did it to me again
i had to disconnect the battery, and switch gpu to discreet from bios for it to populate again
i’m really burning brain cells over this
if you end up finding a permanent solution please share with me, i’ll do the same
also what did you do to “force” install? really curious on how you force installed and made it accept peak power instead of the 80w
could it possibly be electro static damage? like a mosfet taking some damage from improper grounding? i ask because now mine only shows after i discharge the unit and restart twice after changing the gpu mode in bios on the first boot (without ac adapter plugged in)
and yours isn’t taking to that so a different degree of damage?
Force installing the drivers is right clicking the “unknown device” or “Generic display adapter” in device manager, going to “Update driver” and then using the “Have disk” method to specifically select Nvidia drivers. you then need to do the same thing for the Nvidia Platform Controller.
That Nvidia Platform controller is what allows the GPU to draw 175W again.
i have spent hours and hours looking into this and from what i can tell, there is some type of corruption at the DSDT within the BIOS which causes the machine hardware ID to mismatch which in turn stops the Audio amplifier to enable as well as the Nvidia hardware ID not to be recognized. (This is based on a lot of digging using ChatGPT / Claude).
As of right now though i have a working GPU but still no usable audio.
I appreciate the help man. I’m going to give up on this issue for now and circle back to it when i gather more patience, at least i’m getting the gpu to work using your method (preciate it btw) for now.
edit:
dual booted linux mint 22.3 and was having the same issue, shortly after i realized secure boot messes with linux nvidia drivers… disabled secure boot annnnd boom
issue gone, can use audio and gpu with no issues
booted back into windows with secure boot disabled and it seemed to fix the issue
i’ve restarted about 10 times since and no problems
not sure exactly what the issue is with the driver not making it past secure boot but hope this helps someone <3
How it started: GPU stopped being detected (fell back to Microsoft Basic Display Adapter) right after an Intel Graphics driver update that bundled a BIOS update last week.
Hardware ID on the GPU: PCI\VEN_10DE&DEV_27E0&SUBSYS_00000000&REV_A1
SUBSYS is zeroed out — same pattern you all found. This is why the official NVIDIA installer refuses to install (“no compatible hardware”), even though:
Lenovo Vantage hardware diagnostic passed the GPU with no errors
Manual “Have Disk” driver install does get it recognized as RTX 4080 in Device Manager
Updating the “NVIDIA Platform Controller” manually helped restore higher power draw
Also now getting Code 28 on “Intel High Definition Audio” (internal speakers dead) — tried every audio package available for this model (Serial IO, Realtek, Intel Smart Sound Technology), none fixed it. Suspecting it’s the same root cause hitting audio identification too.
Checked Lenovo’s site/Vantage — no BIOS newer than N2CN28WW available for this model/region yet.
Has anyone made progress on fixing the SUBSYS ID via software, or is a board-level flash the only way at this point? Trying to avoid sending it in for repair since I need it daily for work. Any guidance appreciated.
Hi, I’m having the same problem with a Legion 7i pro 13900hx rtx 4080, only the generic Windows driver. At first, holding the power button for 60 seconds and waiting about 10 minutes, then restarting with the charger, the GPU was at 100% without any freezes. If I completely turned off the laptop and turned it back on, it worked perfectly, but if I restarted, it reverted to the generic driver. Now, even doing this procedure doesn’t solve it, and I just lost the sound too. Did you manage to solve this problem?
ja desanimado e sem esperança de tanta alteração de software que fiz, abri o note uma ultima vez antes de mandar para manutenção, e olhando cuidadosamente verifiquei que abaixo do dissipador na regiao da GPU a placa estava molhada, Ăşmida, com um lĂquido oleoso amarelado, pesquisei e vi que vinha dos Thermalpads, que ja estavam desgastados e que isso era normal, mas resolvi pegar o álcool isopropilico e fazer uma limpesa bem cuidadosa com pincel bem macio,
limpei varias vezes, limpei toda área onde que tinha oleosidade, tinha em casa massa polar da showdog, apliquei em todos os VRM e Mosfets onde tinham pontos de contato, como nos originais, troquei o ptm 7950 e o metal lĂquido, liguei usei DDU removi todo o drive de vĂdeo, reiniciei e tentei instalar os drives originais da Lenovo, a placa foi identificada instalei logo em seguida a atualizado para o Ăşltimo disponĂvel,
Hey everyone - I was both happy and frustrated when reading the thread. Happy because now I know I am not the only person experiencing this issue (16IRX9H with an RTX 4090) since I went through the new automatic BIOS update about 2 months ago. Frustrated because the solution is still not clear and I’ve lost my mind trying to resolve this.
Currently, my computer is recognising the GPU since I’ve reflashed my BIOS through LenovoVantage + turning off all automatic restarts on my computer.
Has anyone managed to find a permanent solution to this issue ?
