Question PC fails to power on, have you swapped in the motherboard and power supply unit already?

F5F Stay Refreshed Hardware Desktop Question PC fails to power on, have you swapped in the motherboard and power supply unit already?

Question PC fails to power on, have you swapped in the motherboard and power supply unit already?

Question PC fails to power on, have you swapped in the motherboard and power supply unit already?

V

VincentNL
Junior Member

24

06-01-2025, 01:59 AM

#1

Initially, I considered the power supply because it’s the oldest component and every time I power it on I hear sparks. I replaced it with a new one. Then I tested it with just the motherboard and some fans connected without GPU or CPU—just barebones setup. The fans spun for a second before stopping completely. No power afterward.

I thought maybe the motherboard itself was the issue. I swapped it out for another one that seems to be working, then reinstalled everything: CPU, RAM, GPU, etc. When I turned it on again, the same problem occurred—fan spins for a second, then stops. Nothing else happens. It always seems like the case fan connected to the CPU_FAN2 header is the culprit. I’ve already tried clearing CMOS but haven’t had success. Please help.

V

VincentNL

06-01-2025, 01:59 AM #1

Initially, I considered the power supply because it’s the oldest component and every time I power it on I hear sparks. I replaced it with a new one. Then I tested it with just the motherboard and some fans connected without GPU or CPU—just barebones setup. The fans spun for a second before stopping completely. No power afterward.

I thought maybe the motherboard itself was the issue. I swapped it out for another one that seems to be working, then reinstalled everything: CPU, RAM, GPU, etc. When I turned it on again, the same problem occurred—fan spins for a second, then stops. Nothing else happens. It always seems like the case fan connected to the CPU_FAN2 header is the culprit. I’ve already tried clearing CMOS but haven’t had success. Please help.

X

xImFizzy
Member

213

06-08-2025, 08:31 PM

#2

Display an image of your system without the side panel. (Upload to imgur.com and share the link)
You swapped out the PSU. Are both PSUs (old and new) modular?
Modular PSU cables won’t work with different PSU models.
All modular cables need to be replaced with new ones.
Using incorrect modular cables might damage connected hardware.
By the way, this test was unnecessary. You can't boot a PC without the CPU/RAM.
And it won’t help you identify a motherboard issue from this.
What were your expectations?

X

xImFizzy

06-08-2025, 08:31 PM #2

Display an image of your system without the side panel. (Upload to imgur.com and share the link)
You swapped out the PSU. Are both PSUs (old and new) modular?
Modular PSU cables won’t work with different PSU models.
All modular cables need to be replaced with new ones.
Using incorrect modular cables might damage connected hardware.
By the way, this test was unnecessary. You can't boot a PC without the CPU/RAM.
And it won’t help you identify a motherboard issue from this.
What were your expectations?

T

TIMchannelYT
Member

54

06-09-2025, 12:41 AM

#3

You need to add the GPU, but your CPU doesn't send a video signal to the motherboard. Attach the video cable to the GPU and monitor instead of the motherboard. The motherboard could have an outdated BIOS, and the Ryzen 5500 might not work properly on it. Updating the BIOS with Matisse, Renoir or Vermeer CPU is necessary before installing the Ryzen 5500.

T

TIMchannelYT

06-09-2025, 12:41 AM #3

You need to add the GPU, but your CPU doesn't send a video signal to the motherboard. Attach the video cable to the GPU and monitor instead of the motherboard. The motherboard could have an outdated BIOS, and the Ryzen 5500 might not work properly on it. Updating the BIOS with Matisse, Renoir or Vermeer CPU is necessary before installing the Ryzen 5500.

D

Darkeos
Senior Member

538

06-10-2025, 07:52 PM

#4

The swapped PSU is brand new and fully modular. I was hoping to see some light from my motherboard during the test. That would confirm it's working? 😅😅😅
Link: https://imgur.com/a/GKqTuS3

D

Darkeos

06-10-2025, 07:52 PM #4

The swapped PSU is brand new and fully modular. I was hoping to see some light from my motherboard during the test. That would confirm it's working? 😅😅😅
Link: https://imgur.com/a/GKqTuS3

P

Purplz29
Junior Member

42

06-11-2025, 03:27 AM

#5

check if the monitor is plugged into the GPU rather than the motherboard? psu is fully connected? some people split the main connector into 10 plus 14 pins on the psu side. connect ram to slots a2 and b2 (2nd and 4th slot from the CPU). update the bios of your working motherboard to support the new cpu.

P

Purplz29

06-11-2025, 03:27 AM #5

check if the monitor is plugged into the GPU rather than the motherboard? psu is fully connected? some people split the main connector into 10 plus 14 pins on the psu side. connect ram to slots a2 and b2 (2nd and 4th slot from the CPU). update the bios of your working motherboard to support the new cpu.