Cpu upgrade no display

[Cap91]

Hi guys recently I upgraded my cpu from a AMD dual core a6-6400 apu to an
AMD
Athlon X4 860K Quad-Core 3.7GHz 4MB Socket FM2+ 95W

My mother board is gigabyte ga-f2a78m-hd2
as well problem here is the pc turns on and works 30 sec and goes of by itself and the display gives no answer as well the upgrade was done correctly infact I put back my old processor and all is fine I just want to understand why it didn't work and how can I fix it I tried removing ram graphics card nothing at all. Plus my supply is 700 w thx for the help in advance.

 

[Cycloid Torus]

Confirm that your BIOS is correct one to fully support new CPU. There are 2 different revisions for this board and the BIOS versions are different as well.

When you upgraded, did you load 'Optimal Default' settings? Did you check for and install updated drivers?

If you have correct BIOS and current chipset drivers and still have issue, please describe boot up process in detail.
POST? Enter BIOS? Safe Mode?

 

[Cap91]

Thx for replying so problem Is I cannot access the boot menu as my display won't come on at all so only things that start are fans both cpu and the main one plus graphics card start as well but everything else no sign of life then after that it just shuts down by itself and no cpu I just replaced it without modyfing nothing else should I install drivers of the new cpu before I put it or is there something missing to the process I am doing?

 

[Cycloid Torus]

Current drivers (and BIOS upgrade as needed) from manufacturer's website can be installed while using older CPU.

Athlon X4 860K is not an APU, so it relies on video card which may require specific setting in BIOS. (https://www.amd.com/en-us/products/processors/desktop/athlon-cpu)

Confirm that your BIOS is correct one to fully support new CPU. There are 2 different revisions for this board and the BIOS versions are different as well. It would be a bad idea to get this confused.

Download motherboard manual from manufacturer. Download manual for video card from manufacturer as well. Be certain of your revision number. Follow steps with care.

When you upgrade and enter BIOS, load 'Optimal Default' settings.

If you have correct BIOS and current chipset drivers and still have issue, please describe boot up process in detail.
POST (single short beep means good)? More Beeps (describe in detail)? Entering BIOS? Booting in Safe Mode?