Well you G75 battery would be about 4 years old by now?
Fans not spinning up how long has it been since you cleaned the fans and blown the dust out of your cooling system? If you fans aren't being impeded dust holding them back you probably are having a hardware issue. Are you temp going up? these fans only increase speeds depending on temp of CPU and GPU
G752VY-DH72 Win 10 Pro
512 GB M.2 Samsung 960 Pro
1 TB Samsung 850 pro 2.5 format
980m GTX 4 GB
32GB DDR 4 Standard RAM
Z97 PRO WiFi I7 4790K
Windows 10 Pro
Z97 -A
Windows 10 Pro