Question PC - CPU Error or Wont Post

[CatKai]

So I have a broken PC, the PC is old and I want to fix it again after checking it. It seems like the main problem is the CPU. And if I tried looking for information on the internet it said it could be a problem that the voltage on the PSU wasn't being conveyed enough to the motherboard.

Yes, I use this PSU, but I remember having problems in the past. When I want to shutdown the PC, I have to force it to turn it off (press the turn off button) I can't do it using the normal method and if I want to use the normal method, the PC is still on but the fan is already off.

The last thing before my pc crash, was it freeze like i open up my youtube and leave it for like 1 hour while going to buy some snack and after i comeback it just freeze there i havent had a time to check anything so i force turn it off then trying to turn back on, and nothing happen.

Things I've tried:
- Reset CMOS
- Reset the ram position & placing 1 ram only
- remove everything (except the fan on the motherboard) then turn it on.
- check the pins on the motherboard (I'm afraid something might come loose) to be honest, I'm not sure if it's loose or not, it's small hahaha

*CPU and DRAM Light On

https://imgur.com/6lUjq1E

Specs:
CPU: Processor Intel i5-9400F
CPU cooler: Standard Intel Cooler
Ram: 16GB/ 2GB each.
SSD/HDD: 500GB HDD and 250GB SSD WD Blue
Chassis: Cube Gaming, with 6 fan
2 top, 3 front and 1 back ( not being used currently)
OS: Windows 11
Monitor: dual monitor, 1. 14 inch View Sonic and 19 inch LG
Motherboard: Asrock Phantom Gaming 4
Processor: Intel i5 gen 9
VGA: Nvida Geforce 1060
PSU: PRIME premium 80Plus (https://primegaming.id/premium-power-supply/)

This photo shows an indication that the CPU and RAM lights are on.

And on video if i let it run for couple minute it will turn it off, and turn it on again.

Note : im broke so i dont have any pc.parts that i can test with, and now i.want to buy
The parts. I'm suspecting a problem with, processor, motherboard or PSU. But i cant decide which to buy first cause I dont have enough money huhuhu...

So i was hoping anyone would happen to know or experience this situation and give me opinion what should i buy first or fix it with everything i have.

Thank you have a great day.

 

[Dark Lord of Tech]

More detailed specs would help.

 

[Lutfij]

You've generically listed your specs for the culprit build above. We will need more info. In fact, when posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time.

PSU: PRIME premium 80Plus

https://primegaming.id/premium-power-supply/

Is this the PSU you're working with?

 

[CatKai]

You've generically listed your specs for the culprit build above. We will need more info. In fact, when posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time.

PSU: PRIME premium 80Plus

https://primegaming.id/premium-power-supply/

Is this the PSU you're working with?

Hy!, i"ve updated the spec. And yes that the PSU im working with its new PSU i bought last year...

 

[CatKai]

UPDATE: So I just bought a new motherboard and new processor, and after installing new parts, my computer works perfectly fine.
so it seems the problem lies on either CPU or motherboard. But I'm going to assume the CPU is the main problem.