Mobo won't power on. Help please!

[mudrawker]

I just replaced what I think was a faulty Power Supply and am trying to figure see if the new Power Supply works OK. So far I only connected no. 4 and no. 8 but for some weird reason, it doesn’t want to seem to fire up (no power) when I press the power button in the front of the PC.

Edit: The Motherboard powers on when No. 8 ATX Power Connector is plugged in but when I try to add ATX 12V Power Connector (No. 4), the Mobo does not power on. I am assuming the ATX 12V Power connector is meant for the CPU? Do I have a dead CPU?

[ATTACH type=“full”]6014[/ATTACH]

[mudrawker]

Ahh I realised I put the wrong cable (PCIE) into the ATX 12V. Mobo now starts fine but the issue is that the mobo powers on but turns off automatically after 5 seconds https://www.bleepingcomputer.com/for...efault/sad.png

Here’s a clip:

[MEDIA=youtube]IyfWZQ0MC6Y[/MEDIA]

[veeg]

Hello

Please give us your complete pc spec’s.. Also the name and model of your psu replacement. What was the issue with the old psu?

[mudrawker]

Apparently, nothing was wrong with the old PSU as it was exhibiting the same symptoms. I thought it might have been the PSU thus why I replaced it.

Mobo: ASRock Z77 Extreme-4M
CPU: Intel I5-3570 3.4Ghz
Add-on GPU: None (using Mobo GPU)
RAM: G.SKILL [ NT ] F3-10600CL9S-4GBNT 4GB
PSU: Black.Sir 500W PSU (This is new) https://www.grameencomputerbd.com/pr...-power-supply/

[veeg]

Have you made any changes in hardware or software and or updates prior to you changing the psu?

[mudrawker]

Nope, I re-installed my OS on this current hardware and kept it in the store room for about 9-12 months, took it out recently and had this issue.

[veeg]

How old is the pc?

[mudrawker]

7 Years old? lol

[phillpower2]

Just a heads up Veeg,

Have been helping mudrawker elsewhere where it has come to light that the heatsink has been removed and replaced from atop of the CPU, problem is that the HS was replaced without cleaning off the old thermal compound then correctly applying a fresh amount.