Hp fan replacement/compatibility issue

[Knpvt5]

 

 hey , yesturday I bought the new fan from local shop in nehru place for my hp pavillion 15-eg laptop , in the image you can that the top one fan is the new fan that I bought, while the bottom one is the original fan, the service pn number of the original fan is M20334-001, while the new one that I bought from the local shop has service pn number - N03506-001, so when I installed the new fan in my laptop, the structure of the both fan is same and pin is also same and is also fitting perfectly but this new fan is not working in any either side, while the old/orignal one is working on both the side why is this problem , it there internal circuiting difference between the fans model. Please help

[Knpvt5]

 what I mean is that my laptop has two fan fir cpu and gpu, the cpu fan is the original one and the gpu fan that I bought new one , so I test the cpu fan in both the cpu and gpu port it is working but the new one is not working on any of the port, yes the voltage and ampere is same as the original one, since I bought it new so I am doubting that the problem is in the circuit system, also the seller didn't tested the fan in front of me before selling it to me, so it can be DOA too, also my hp laptop shows be system 90B error on startup

[Knpvt5]

hey i got the new fan installed in my laptop from the local shop, the fan is working fine and is also keeping the temperature below 80% even when i play the AAA games, no sound, no vibration, but that fan is failing the UEFI hardware diagnostic fan speed test, why ?

[Kuroi_Kenshi]

Hi @Knpvt5,

Welcome to the HP Support Community!

Thanks for reaching out about your query regarding your replacement fan!

We're thrilled to have the opportunity to assist you and provide a solution.

Thank you for the update. I'm glad to hear that the new fan is running fine and keeping your laptop cool even under heavy load!

Regarding the UEFI hardware diagnostic fan speed test failure:

Even though the fan physically fits and spins, it’s possible that the replacement fan you purchased (Service PN: N03506-001) does not have the same internal circuitry or RPM feedback signal as the original fan (M20334-001).

The diagnostics tool relies on that feedback signal to confirm speed and functionality. If the replacement fan doesn’t send the expected signal (or uses a slightly different standard), the system may report it as a failure even if it is working properly.

This is why you’re seeing a mismatch between actual performance (working fan, stable temperatures) and the UEFI test result.

To ensure long-term compatibility and to avoid recurring 90B fan errors, we recommend using the exact HP service part number (M20334-001) that your laptop was originally shipped with. Fans with different part numbers may look identical and work to some extent, but they may not fully pass HP’s diagnostics due to these design differences.

If the laptop is stable and temperatures remain normal, it should be safe to continue using the current fan. However, if you want diagnostics to pass cleanly and ensure full compatibility, replacing it with the official part would be the best option.

I hope this helps.

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