Solved! HP Envy x360 15-BP152NR CPU max speed locked due to fan error


Feb 12, 2020
Hi all, I have HP Envy x360 15-BP152NR and recently its fan started making weird noise. I tried to look for a compatible replacement here in India but couldn't find it anywhere (neither online nor in the market and even HP doesn't have it in stock).
So, then one laptop repair guy somehow installed a CPU fan of another laptop in my laptop. The fan does excellent cooling as it always runs on full speed but my laptop isn't recognizing it. It shows HP's 90B error (fan and cooling related) everytime I boot the laptop. I'm easily able to skip the warning or this error message and system boots up perfect fine with good speed.
But just within like 30 seconds of windows startup my CPU's maximum speed is locked at 0.39Ghz which I believe is because the motherboard or CPU thinks that there's no fan in the system and it locks the speed. is there a way around to unlock this maximum CPU speed.
it's Intel i7 8550U (and to be clear with this incompatible fan there's no heating issue as it runs on full speed all the time so the CPU temperature is below 40 degree celcius all the time.)

Sorry for my bad English. I would highly appreciate any suggestions and advise on workaround to unlock the real CPU speed with this incompatible but working fan. Thanks!
I would take it back to that tech and have them check their work. A change in the fan shouldn't give you such issues. They did the work, they should do it right and resolve any issues caused by their work.