Unusual actions during sleep, shutdown, and power-off phases on your PC?
Unusual actions during sleep, shutdown, and power-off phases on your PC?
I've noticed unusual behavior over the past two months with my 4-year-old self-built Ryzen PC.
I've uploaded two YouTube videos to highlight the issue.
In Scenario-1, when I power on the PSU, the system lights—specifically the HDD/system activity and CPU fault LEDs—come alive at 0:08 seconds as I switch the power. They stay illuminated until I press the power button on the case to activate the system.
In Scenario-2, during shutdown, the power button light turns off correctly, but the HDD/system activity LED stays on with all fans running at full speed until I turn off the PSU power switch.
Could this indicate a problem with my PSU or the motherboard? I suspect the PSU might be failing, though the PC still works normally. My gaming laptop is also present, so usage has been limited.
Please help me figure out what's going on.
As per the Motherboards User Guide/Manual, ensure you double-check the case and front panel connections. It's quite simple to confuse them. The specific motherboard is available here: https://download.msi.com/archive/mnu_exe...LUS_EN.pdf. Make sure you locate the relevant User Manual. Front panel connections are detailed on physically numbered Page 33.
The motherboard ->
https://download.msi.com/archive/mnu_exe...MAHAWK.pdf
I've verified all connections on my case's front panel IO and switches with the motherboard, everything seems fine.
Since 2020 I haven't adjusted anything, but this problem began recently. After restarting it again, the results were the same.
🙁
Set up a brand new CMOS battery following the instructions in the User Guide/Manual for installation.
Do you possess a multimeter and understand its operation? Or do you know someone who does?
Note:
https://www.lifewire.com/how-to-manually...er-2626158
The PSU is not operating under load; any voltages outside the acceptable range would indicate a problem with the power supply.
I believe we've discovered something quite unusual with this PSU, haha.
Measurements taken below using the GND probe at Pin 24 when the PSU wasn't powered on showed:
Pin 1 – 0V
Pin 2 – 0V
Pin 4 – 0V
Pin 6 – 0V
Pin 9 – 5V
Pin 10 – 0V
Pin 11 – 0V
Pin 12 – 0V
Pin 13 – 0V
Pin 14 – 0V
Pin 21 – 0V
Pin 22 – 0V
Pin 23 – 0V
When the PSU was powered on, the readings changed:
Pin 1 – 3.39V
Pin 2 – 3.39V
Pin 4 – 5.05V
Pin 6 – 5.06V
Pin 9 – 5.05V
Pin 10 – 12.03V
Pin 11 – 12.03V
Pin 12 – 3.39V
Pin 13 – 3.39V
Pin 14 – -11.53V
Pin 21 – 5.06V
Pin 22 – 5.06V
Pin 23 – 5.06V
What caught my attention were the trends when I gradually turned on the PSU's toggle switch at the back, but didn't power it up yet.
The voltage changes were consistent with what I expected, though not as described in Section 4.1.3.1 of ATX Spec.
Video recorded during the test.
Looking forward to your thoughts; please note that my formatting here should be clear for easy understanding.
I don't recall observing the voltages dropping as you noted.
Uncertain about the nature of those slow discharges, but it's possible a capacitor is releasing energy....
Still, let's verify the steps:
Did you remove all connectors? The red wire in the video is at Pin 24 (COM) - correct?
Observed 5 volts on Pin 9 (standby voltage according to Lifewire).
Are you using or referencing the voltage specifications from Page 20 of the ATX manual - correct?
Check the connectors via the Lifewire link. I didn't see a jumper wire - Pins 15 and 16 (Step 5) in the video.
Yes, that was Pin 1 (+3.3v). The red wire acts as a positive probe for my multimeter, and during recording I measured Pin 1 (+3.3v) relative to Pin 17 (COM). Correct values with the jumper wire connected are shown on the second table of my post above (Pin 14 reads -11.53 volts). My video aimed to demonstrate that without connecting the jumper wire between Pins 15 and 16, I wasn't sending the PS_ON command – correct? Now, as soon as I power on the PSU's switch, voltage appears on the pins listed in the third table, which I found unexpected since my PSU wasn't supposed to be on. I hope that clarifies things 😅
Not certain about this. It seems like a classic "apples and oranges" situation...
Investigate using online resources about Standby Voltage.
For instance, you can check articles such as:
https://www.techspot.com/article/1967-anatomy-psu/
Many devices remain powered up even when turned off, to allow for a faster start.
This is usually shown by an LED indicator.
Some people think a "stand by" setup is inefficient and should be ignored.
The main goal is to understand what's happening in your setup.
If turning on the PSU switch reveals voltage that shouldn't exist, then the unit may be faulty.