Pwr led (case) stays on

  • Thread starter Thread starter terry tiller
  • Start date Start date
T

terry tiller

A7v266 mobo. corsiar pc2700 (256), maxtor 40gb 7200rpm, windows XP Pro,
enlight 400w PS. Ocassionally will not post. Notice that pwr led coming
from frt panel header (pwr light on case) stys lighted all the time (whether
powered up or not). I know this is not normal and may be a indicator of my
problem. Any ideas appreciated.
 
PWR(POWER)Led cannot stay on if pc is not on.
The PWR (Green)led is supposed to connect to the PWR led pins on the
Motherboard.
It is to show that the PC is on.
The IDE Led(Orange or red)(known as HD led)is the one that connects to
motherboard IDE/HD led pins.
This led should only be on when there is disk activity.
 
I understand that. Have built several over the years. Never seen anything
like this. Only way to make it go out is to unplug the power supply. I
just loosened the mobo attaching screws, thinking I had a short to the case,
no luck. TT
 
I understand that. Have built several over the years. Never seen anything
like this. Only way to make it go out is to unplug the power supply. I
just loosened the mobo attaching screws, thinking I had a short to the case,
no luck. TT
Click to expand...


I never seen that happen either, only suggestion I can make would be to
test the board out of the case and check to make sure there are no
unused standoffs on the case that could have been shorting out on the
board.

Ed
 
PWR(POWER)Led cannot stay on if pc is not on.
The PWR (Green)led is supposed to connect to the PWR led pins on the
Motherboard.
It is to show that the PC is on.
The IDE Led(Orange or red)(known as HD led)is the one that connects to
motherboard IDE/HD led pins.
This led should only be on when there is disk activity.
Click to expand...

I doubt that anyone who posts here doesn't know that!
What you take us for, complete morons? LOL!
Ed
 
T said:
I understand that. Have built several over the years. Never seen anything
like this. Only way to make it go out is to unplug the power supply. I
just loosened the mobo attaching screws, thinking I had a short to the case,
no luck. TT
Click to expand...
Just loosening the screws may not relieve a case short. It's best to
remove the board and run it on a non conductive surface. Before doing
that, I would remove the 2 IDE ribbon cables to eliminate a short in any
of the drives that could cause the light to stay on. Might also remove
the IDE Light connector from the Mobo to insure the case wiring hasn't
shorted together. Also would remove all power and clear the CMOS before
I'd pull the board.

Rob
 
I have tried another led light lead from another identical case, same thing.
I have cleared the CMOS 2x's. Will now try your sugguestion of completely
removing the board from case. Will keep you posted. TT
 
"terry tiller" said:
I have tried another led light lead from another identical case, same thing.
I have cleared the CMOS 2x's. Will now try your sugguestion of completely
removing the board from case. Will keep you posted. TT
Click to expand...

I would try a power supply swap. I've seen one post here, where the
poster had a bad power switch on the power supply - the power switch
would not interrupt the flow of current to the supply, so the supply
would run until unplugged.

Another possible reason, is the motherboard may be pulling the PS_ON#
signal low (it is active low) when it is not supposed to. PS_ON# is
one of the signals on the ATX 20 pin power connector.

But, as power supplies have a much higher failure rate than logic
circuits, swap the power supply first.

Before spending money on a new supply, you could test it outside the
case. The supply will start to run, only while PS_ON# is connected
to one of the COM pins. You should hear the fan in the PS running while
PS_ON# is connected to COM. The fan should stop when you remove your
test wire from PS_ON# to COM. If the PS continues to run with the
test wire removed, then the PS needs to be swapped.

For the pinout of the ATX power supply connector, see page 19 of:
http://www.formfactors.org/developer/specs/atx/atx2_1.pdf

PS_ON# is next to the locking tab, so should be easy to find.

HTH,
Paul
 
I give up. Swapped PS. Removed mobo from case. Ran it on the box. Nothing
helps. Power light stays on as long there is pwr to the PS.

and so it goes...

TT
 
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