Question No Display, CPU fans spin but SYS fans do not

[hgin28]

A while back, my comp was running fine and i stepped out to do some work on my car. When I came back, my computer was powered down, no response when I push the power button; so I figured it was either the PSU or the Motherboard. I bought a new PSU and replaced it, still no power, so I bought a new motherboard... same exact model so I wouldn't have to worry about any compatibility issues.

Now there is power but there is no display. And I noticed that only the fans that are plugged into the CPUFAN1 & 2 ports have power, but fans plugged into the SYSFAN1, 2, & 3 ports aren't spinning. I also noticed when I plugged in my graphics card, the GPU fans aren't spinning either.

Is there anything that can cause this? I've searched around and everyone keeps telling me to try clearing the CMOS or whatever, but I've left the CMOS battery out for an hour and it still has the same issue.

So far I've tried replaced or tested by swapping:

Power supply
Motherboard
RAM (had spare sticks)
CPU (had spare i5 from when I upgraded to i7)
With/Without Graphics card

What are the chances that this board is bad? I really don't want to try a 3rd motherboard..

Please respond with suggestions, I'll try anything. Thanks!

 

[Lutfij]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. List them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

You will also need to include the parts you added on and replaced as well as the slots used for the rams used.

 

[hgin28]

Gotcha..

CPU: Intel Core i7 8700k
Motherboard: MSI Z87-G43 Gaming
RAM: 2x 4GB DDR3 2400Mhz
PSU: EVGA Gold 750
GPU: EVGA Geforce GTX 1080
SSD: 750 GB
OS: Windows 7 Ultimate
Chassis: Unsure.. not sure if this matters, but the heatsink fan is a Corsair Hydro Series H100 liquid cooling

Tested with CPU: Intel Core i5 (duno the hertz)
Old PSU: EVGA Gold 750 (same model, was under warranty)
Old Motherboard: same MSI Z87-G43 Gaming

I've tried with just the minimum components connected; CPU, motherboard, 1 stick of RAM, PSU, monitor, keyboard, connected to onboard DVI port for graphics

I've checked with two different monitors as well, all same result.. power to the board, LED lights on GPU, board, and heatsink fan (corsair logo lights up on the heatsink), but no power to other fans or GPU fans..

Computer is pretty old, I'd say at least 5 years old?

 

[hgin28]

Also, no POST/beeps when I power on.. I only hear the fans spin and that's it.