CPU getting shutdown when switching ON!!

[Ravi S]

I am so frustrated to the point that I am not thinking straight. Tried every tricks under the sleeves but man.. this problem is some pain in the butt.

I am using Corsair V2 TX650 Watt to power up my new RIG- 3700x + Aorus x570 Elite and when every i try to start the same it is responding for 20-30 seconds then getting switched off. The same is happening with my old LGA 775 Mobo (945GCCR) and Dual core.
That power supply was sitting idle for more than 2 years i suppose unfortunately I do not have extra PSU to verify. 

 

BTW I have tried:

1. Exchanged RAM on either slots
2. Checked the power switch of the Cabinet but its fine. after power on I removed that cable from mobo just to make sure the power button on the cabinet is not jammed.

3. Removed CMOS battery and waited for some time after pressing the power button then put it back there.

4. Checked for the loose connections

5. Properly installed the CPU fan

 

Interestingly after switch on CPU is not going to BIOS mode. Can someone help with this..

 

Its like i have  8 mills but I cannot spend.