Question Do you think my PSU is the issue?

[GracefulDead]

In 2017 I build a pretty expensive gaming PC. The PC at the time had a 1080 ti 11 GB, AMD Ryzen 7 1st Gen 1700 with a PSU of EVGA SuperNOVA 750. After using it on and off for about 6 years I thought that Cyber Monday was the perfect time to update my motherboard, cpu and watercooler. After putting everything together the GPU lights would turn on and off until the pc would die and reboot again. Keep in mind the Pc would never boot into the Bios while this was happing. So I unplugged the GPU and then the water cooler RBG and the motherboard RBG turned on for the first time. After this happened It made me think that the PSU is the issue, but 750 W should be enough to power the whole PC. Do you think I should replace the 6 year old PSU or is it something else?

 

[Lutfij]

6 years is a long period to hold onto a PSU, though in retrospect, in order to rule out one part for being faulty, you need to borrow(not buy first) and then power the platform with said borrowed PSU, from a friend or neighbor(who happens to own a reliably built unit with at least 650W of power for the entire build.

Can you please list the specs to your build like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the parts that were replaced with upgrades in the form of a before and after for the sake of clarity.

 

[peterf28]

6 years is long period for PSU ?? Is this intention valid, legit & confirmed ? I have my PSU for 11 years nowand planning to reuse it in my next build (i5-13500) .

 

[Vic 40]

With a 5 year warranty might 6 be a problem.

Would be good to give those specs that are asked for. Both the old and new.