Ok, I took a guess and replaced the BIOS battery as the manufacturing mode seems to be managed by BIOS. And after that the problem went away. Alt+F during the next restore from hibernation and no more crazy fans. PS. I also made a typo in the model number, it is 5584.
Hi everyone, Two days ago my Inspiron 15 5584 started to start in manufacturing mode. It appears both after hibernation and after reboot. The only visible/hearable thing that happens is that the fan goes crazy but the system starts normally. I pressed Alt+F when prompted. This moves the laptop back to normal operating mode but the manufacturing mode (a.k.a. crazy fans) returns after the next hibernation or reboot.  After I press Alt+F, the screen briefly shows 8AC6D992 message in the upper left corner which I found might be related to missing Service Tag, but the correct tag is shown in both BIOS and OS. There was no hardware change. The only software change was an update to Dell SupportOS. I revert the system back to the time before, and it didn't help. I tried to restore BIOS default, it didn't help. Any ideas how the manufacturing mode can be disabled and don't come back?
Inspiron 15 5884 manufacturing mode malfunctioning