My name is Rohit and I work for the Social Media and Community Team at Dell.
Please let me know that after removing the USB Fan if system boots up and Harddrive is detected or not and you can also check the harddrive status by going to system setup by tapping F2 on Dell logo, Please let me know the status and you can also do system set-up default by pressing F9 on System setup screen.
I might help you more please share the system model.
Please reply back with the results.
Glad to assist you!
Thanks and regards
Dell Social Media Responder