Hello, I had the same problem(fx705dt model). Firstly I thought I will have to replace the fans because I owned it about 3-4 years. I did and for some period of time it worked. About 2 days ago, it started again and I searched on youtube etc. I saw someone saying that if you change gradually from Silent mode to Performance and Turbo it will fix the case (this specific person told that he did that for a period of time and now his fans are fixxed, tbh it's something you can do for now, but I am warning you that my fans were replaced and still had the same problem, so I am gonna try this solution.)