Question Gigabyte GA-MA770-UD3 doesn't start ?

[thebenjamin]

Hello,
I have an old comupter that I've been using regurally. Suddenly it stopped to respond and now when I try to boot it up nothing shows on the display.
I've tried to check all the connections and everything is firm as it was.
I suspect the problem is the motherboard (Gigabyte GA-MA770-UD3), but not sure how I can pin down the cause for the issue.
When I boot the computer, it gets electrecity and all fans are spinning the GPU's and CPU's cooler, it also sounds like the HD is working.
I tried to remove the RAM sticks and it behaves the same, but it doesn't beep at all (I remembered it should beep for that).

CPU: AMD Phenom II X4 940
Motherboard: Gigabyte GA-MA770-UD3
Ram: G.Skill DDR2 2X2GB 800Mgz
SSD/HDD: Seagate Baracuda ST1000MD010 - 5 years old
GPU: EVGA Geforce GT 710 2GB DDR3 - 4 years old
PSU: Antec VP500PC - 5 years old
Chassis: Antech 300
OS: Windows 10

Update:
After some trials the comupte suddenly starts, but a few minutes later froze. I tried to restart it, and then it came back to the same state as before - nothing shows up.

I would appreciate your help.

Thank you.

 

[Lutfij]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model.

 

[thebenjamin]

Updated the specs.
Also:
After some trials the comupte suddenly starts, but a few minutes later froze. I tried to restart it, and then it came back to the same state as before - nothing shows up.