Probably because the fan does not have an RPM sensor which tells the BIOS if the fan is working properly. Although I have read forum posts from users that had replaced the Dell fan with one that was not Dell but had the sensor and still got an error. The following posts should help. Read through to the end. Just wondering, how many pins was the Dell fan and how many on the new fan you installed?
JOcean
9 Legend
•
12.6K Posts
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January 24th, 2019 06:00
Probably because the fan does not have an RPM sensor which tells the BIOS if the fan is working properly. Although I have read forum posts from users that had replaced the Dell fan with one that was not Dell but had the sensor and still got an error. The following posts should help. Read through to the end. Just wondering, how many pins was the Dell fan and how many on the new fan you installed?
https://www.dell.com/community/Desktops-General-Read-Only/CPU-Fan-Not-Detected/td-p/3444006
salehalsagabi
1 Message
0
April 22nd, 2020 00:00
I have the same problem on Latitude E7440
how I can get the replacement parts ?
what is the part number to order ?