By RMA I meant send it back to the seller (Amazon, bought less than 7 days ago), my bad ;). Anyway, it seems that re-flashing the BIOS fixed the problem (!?). No update, just a re-flash. The bug did not occur during the last 6 days... EDIT : spoke too quick, just got -55°C again, with PWM fans running at fixed speed...
Hi, Really old post, but ran into the exact same trouble : - CPU : i5-7600k non-overclocked - MB : Gigabyte Z270XP-SLI - BIOS F6 - Last BETA version of Aida64. On the attached file, you can see the normal situation on the left (CPU has a positive temp° and CPU-fan is displayed). Sometimes after using the computer for several hours, it suddenly goes to the situation on the right : negative CPU temp° and CPU-fan disapears. At that point, CPU-fan is running at a fixed speed (while it's configured to work on PWM mode). Two years after, is your diagnosis still the same ? Do I have to send it back (I'm under warranty) ?