Keyboard flashing on after shutdown, PSU surging?

[Socio]

I have a Logitech G-15 keyboard which lights up while the computer is running. I noticed last night about 2 hours or so after I shutdown my computer the keyboard would flash on and off, I shut the PSU switch off on the back of the computer and it stopped. It is like the PSU is surging power though my system even though it is shut down.

Sound like the PSU is going bad, it is only about 6 months old?

 

[philipma1957]

may be the mobo. it may be send a brief power on to the psu. what mobo and what psu do you have. oh it could be the power on switch of the pc it could be the problem . three possible places to check.

in a diy pc if it is the pc's power on off switch it is easy to check. turn the pc off and pull the switch cord connected to the mobo from the pc.

so if it flashes on off you know the pc on off switch is not doing it. checking if it is the mobo or the psu can be harder

 

[Socio]

may be the mobo. it may be send a brief power on to the psu. what mobo and what psu do you have. oh it could be the power on switch of the pc it could be the problem . three possible places to check.

in a diy pc if it is the pc's power on off switch it is easy to check. turn the pc off and pull the switch cord connected to the mobo from the pc.

so if it flashes on off you know the pc on off switch is not doing it. checking if it is the mobo or the psu can be harder

Will try that thanks, if it is not the switch, then as far as PSU or MB I guess I will have to pop for a new PSU and if it keeps happening after I install it then it has to be the MB.

 

[Ketchup]

What motherboard is it?

 

[flexy]

it is like the PSU is surging power though my system even though it is shut down.

Your PC is indeed surging power to your system when it's shut down, it's the +5VSB (standby) voltage from the PSU which is always on (unless you switch the PSU off).

This stand-by voltage powers USB, some NICs, keyboards etc. so you have the ability to wake up your PC via keyboard etc. also when then the comp is off. The stand-by voltage is also needed internally to actually power-on the computer when you press the case switch.

The blinking of the KB to me suggests there might be a problem either with the PSU or mobo related to to the +5VSB voltage, a short maybe or a cap going bad. So, worst case scenario, at some time you cant turn on your PC anymore because the +5VSB failed. What PSU is it?