Question Nothing turns on when I plug the 24-pin into the motherboard ?

[jjj22]

So my PC won’t turn on for unknown reasons and I have tried everything from resetting CMOS to taking everything apart and putting it back in. I have made sure everything is compatible. Or thought I made sure.
All my parts (I have no other parts it’s my first time building):

GIGABYTE B550M DS3H Micro ATX
AMD Ryzen 5 3600 & stock cooler
AMD Radeon RX 6750 XT
AresGame AGV 750w (semi-modular)
3 RGB 120 mm fans 3 pin/Molex connector
1 stock fan from case 120 mm 3-pin
Corsair Vengeance LPX DDR4 Ram 32 gb 16x2
Coolermaster Masterbox Q300L

So as I put everything in the first time nothing worked (Although I did connect a display port to connect it to the monitor first I don’t know if that affects anything) and I didn’t know what to do. My first thought was to take out the GPU and the Ram. After that I turned the PSU back on and nothing changed. I inserted the Ram into different slots and nothing happened. I took the entire motherboard out of the case and put the components on it while out of the case and again nothing happened. I made sure to rub my hands on metal surfaces to get static electricity out of my fingers and hands but I’m not saying it isn’t the problem.

Then I realized it might’ve been the 24-pin connector. So I put the connector into the “tester” and in fact the only things that turned on were the things that weren’t connected to the motherboard, the 3 RGB fans and of course the power supply was running. After noting this, I plugged the 24-pin back to the motherboard and turned the PC back on. I saw a very unnoticeable light on the case’s adjustable I/O panel where there are the USB’s , mic jacks and whatever. I noticed the light turning on when the 24 pin was connected to the motherboard. The confusing part was, it was the only thing that turned on that was connected to the motherboard. (nothing would turn on when the 24 pin of the PSU is connected to the MB.) No fans would turn on just the case LED.

I don’t know if it is the PSU because the “tester” worked for the fans and I don’t know if it is the motherboard because of the case LED wires that are connected to the motherboard when the actual 24 pin is connected. I made sure to check the CPU socket to find any bent pins and to check the CMOS and the CMOS battery. Nothing is wrong with the monitor just the PC. It might be the CPU connector from the PSU but again I am not sure what the problem is, When I first assembled everything together of the PC nothing originally worked so I didn’t know what to do. I looked all over the internet and watched countless videos trying to hope that I don’t have to replace anything. I would love help because I have been trying different solutions for hours.

 

[jjj22]

I’ve tried the power supply into an older I motherboard from a very old computer I apparently had and the motherboard happened to power on. So in fact i have slimmed narrowed it down to either the cpu or the motherboard itself which I am suspecting.

If it was the motherboard I would replace it and return it(hopefully) on Amazon. It probably happened from static shock or something.

 

[faalin]

I would say you need a new PSU.

According to this link from tomshardware LINK
"The Aresgame AGS750's performance is poor and its build quality is mediocre."
"The AGS750 is supposed to have Gold efficiency, but in our tests, we discovered that it could not even compete with several Bronze-rated PSUs"

A PSU tester does not show much, other then yea it will turn on. With no load on the PSU everything is fine, try booting an entire system and it has issues.

If you can try and barrow a PSU from a friend to see if the computer will boot.

 

[jjj22]

Okay I will try that, I do not have access however to another PSU but I will get a new one. I will get more known brands like Corsair, even though the reason I got AresGame was because it was cheaper than anything I saw. Thank you for the help, i was getting desperate. I will update this thread when I try a new PSU.