Question Red CPU light. No monitor display and no sign of keyboard/mouse lights

[xxmccawxx]

I've talked to so many people from geek squad to cyberpower pc. I was wondering if you could help me figure out whats wrong with my pc. When i turn it on the pc itself runs fine, however the monitor says there is no hdmi connection (i've tried so many hdmi cords) and the keyboard and mouse do not turn on. At first i thought it was a faulty hdmi port so i got a new graphics card. Switched it out and it didnt work. Then someone else told me it was my cpu so i bought a new one and switched it out (yes it was the same cpu). I still had the same problem and then another person told me to get a new motherboard. I'm still having the same issues. I have no clue what else it could be.
Please help!!

Motherboard: MSI MPG Z390
Graphics Card: Radeon RX 560 4GB
CPU: Intel I5
Thanks

 

[rgd1101]

model of this i5?
make and model of the psu?
ram?

 

[xxmccawxx]

model of this i5?
make and model of the psu?
ram?

model of this i5?
make and model of the psu?
ram?

CPU: Intel Core i5 6600k
Graphics Card: Radeon RX 560 1196M Core
RAM: Adata (it came with the pc when i bought it years ago)

 

[rgd1101]

300 chipset only work with 8th/9th cpu. 6600k is 6th gen
go to MSI MPG Z390 motherboard website cpu supported list for the supported cpu

what the old motherboard? check for bend pin on the socket?
make and model of the psu?

 

[xxmccawxx]

300 chipset only work with 8th/9th cpu. 6600k is 6th gen
go to MSI MPG Z390 motherboard website cpu supported list for the supported cpu

what the old motherboard? check for bend pin on the socket?
make and model of the psu?

I discovered that last night. On best buy's website it said the intel i5-6600k was okay but on the box it says otherwise. i ordered the intel core I5-9400