Question Motherboard LED Flickers and Keyboard LED automatically turning ON, after switching ON the PSU, Is this Normal?

[bancevicj]

Hello,

I just build another PC.
I would like to ask or have an understanding on the flickering of motherboard led and keyboard led automatically turning on after I switched on the PSU.
but, when I shutdown my system unit, all LEDs are completely turned off, weird..

Video (after turning on the PSU):

Another video: https://www.youtube.com/shorts/sgVUYh4ERmQ

Video (after shutting down my computer):
https://www.youtube.com/shorts/B0WSiIjY3TA

What triggers the motherboard led to flicker and for the keyboard led to automatically lights on? When I am not yet powering on my CPU...

NOTES:
BIOS, "Turn on LED in S5" = disabled
I already doubled checked the wirings and it properly attached to where it belongs, no loose wirings.

COMPONENTS:
ASRock B450M STEEL LEGEND
FSP Hydro GD Gold 650W 80+ Non-Modular HGD650 Power Supply
Fantech Mechanical Keyboard RGB Macro Supported Gaming Keyboard MAXPOWER MK853 BLUE
PNY XLR8 Gaming EPIC-X RGB™ DDR4 3200MHz - 16GB
AMD Ryzen 5 5600G

 

[Paperdoc]

Mamy systems are set in BIOS Setup to "wake" from any keypress on the keyboard, or from any action of the mouse. To do this, even when your system is "Off", there is power supplied to those devices and the mobo has a small circuit running to watch them for input signals. The way you prevent ANY start-up is to turn off the power switch on the back of the PSU - that really turns the PSU completely off.

 

[bancevicj]

Mamy systems are set in BIOS Setup to "wake" from any keypress on the keyboard, or from any action of the mouse. To do this, even when your system is "Off", there is power supplied to those devices and the mobo has a small circuit running to watch them for input signals. The way you prevent ANY start-up is to turn off the power switch on the back of the PSU - that really turns the PSU completely off.

Ok I understand you mean for the PSU, What about the motherboard leds blinks/flickers, is that normal? You have any idea? thank you so much with your reply, very well appreciated.

 

[Paperdoc]

To be clearer: when the switch on the back of your PSU is in the "On" position, even though your computer us "Off" and doing nothing, your KEYBOARD and MOUSE may still receive a low power supply just to they can send a signal back to the mobo, AND the mobo has a small monitoring circuit running looking for that. THAT is how pressing any mobo key can START your computer. (Of course, you also can "turn on" using the On / Off button on the front of your main case.) When you turn that back switch to OFF, there is NO power at all supplied to anything, and you cannot start up by pressing a key OR the front panel button.

So, when you turn ON the back switch, one impact is that the keyboard and mouse immediately get that basic power supply. Apparently your units have their own lights that turn on whenever the units get power.

 

[bancevicj]

So, when you turn ON the back switch, one impact is that the keyboard and mouse immediately get that basic power supply.

What is the difference after I shutdown the system unit? As you watched my video on shutting down the pc, keyboard led turns off also, the "basic power supply" is no more, Why?

 

[Paperdoc]

That IS an interesting question. I can only suspect that the keyboard itself has some means of detecting that the reason it is supposed to "shut off" is that the mobo said so. BUT IF the keyboard had NO power and then got some when the rear switch was turned on, its default start-up state is to turn on its lights until told otherwise. Speculation, of course.

 

[letmepicyou]

Have you plugged the keyboard into another computer to see if the problem persists?

 

[bancevicj]

Have you plugged the keyboard into another computer to see if the problem persists?

Yes i plugged in to another pc, its not powering on when i switched on the avr+psu. Only powering on, when i switched on the CPU power button

 

[letmepicyou]

Yes i plugged in to another pc, its not powering on when i switched on the avr+psu. Only powering on, when i switched on the CPU power button

Well, without another identical keyboard to compare to, it's hard to say if that's just the way this keyboard behaves under the particular power conditions your computer produces, or if there is some inherent defect. I suppose your only option at this point is A: contact the manufacturer and ask them directly, or B: order an identical keyboard and see if the "problem" manifests there as well.