I'd suspect CPU problem, is it possible to check if there's any bent pin in the CPU socket, or check if there's PCB bent of your CPU, or any bad contact on CPU pins/DIMM slot pins.
You could buy a Bluetooth PCIE card just like your ASUS wireless PCIE card, or a simple USB Bluetooth device, or if you don't have budget concerns, you could replace your ASUS wireless pcie with the following kind of wireless+Bluetooth card...
If you're using Windows 10 then this might be your solution:
https://www.reddit.com/r/Windows10/comments/3g52o0/fix_for_installing_windows_10_on_an_intel_g3258/
No, you can't and never think of it. The PCI-E connector (6+2 one) has 3 x 12V lines and 5 ground, and the CPU power connector (4+4) has 4 x 12V, and 4 ground, all you get is a direct short between 12V and ground if you do that because the pins definition for 12V and GND for CPU power and PCIE...
You switched the option to Integrated then you'll need to change your graphics output to on board HDMI/DVI to have display. Or you can remove the CMOS battery or short the JBAT to clear CMOS:
https://www.youtube.com/watch?v=rdHH9KrceR0
So that your BIOS will be all reset to default settings.
So it's a solid light not flashing, correct? You could also try disable "Intel Adaptive Thermal Monitor" option under BIOS--OC--CPU Features, and see how it goes.