Thread: Commell LS-372 + USDC20D shut down controller

I made all test.

I am quite sure it is 5V powered up.

When the motherboard is powered but off, first pin of the power button header is nothing (not grounded) and the second is +5V.

If I short to ground the first pin, the second or both, nothing happened. But if I supply +5V to first pin, the motherboard wake up.

My shut down controller do not short pin together, it shorts pins to ground. But ground, this is not +5V so the motherboard do not wake up.

coucouillu> You need to create a small circuit with a transistor and a few resistors, to power the ls-372 from an mpegbox usc20d, here is the schematic : http://www.mpegbox.net/forums/viewto...dd525874fbeb4e

I have the same combo of the ls-372 and usc20d running in my car, so it works fine with this little curcuit.

Originally Posted by _Dejan_

Did you fix your problem? How?
Im buy LS-373 board and need one good power supply for it.
Must have:
low voltage threshold
Normal work with S3 sleep

I don't know LS-373 power up system but I can tell you that the LS-372 need +5V to the power button to boot up, or a power supply which shorts the 2 pins of the power button together.

If you choose a power supply/shutdouwn controller which shorts to ground the power button like do the µSDC20, it won't work.

I was obliged to modify it :

Originally Posted by Coucouillu

I have found a solution.

I was right. LS-372 needs a +5V signal to power up and the uSDC20 use a "short to ground" signal.

So I modified the uSDC20 adding a little home-made circuit with 78L05 5V regulator a PNP transistor. I also modified routage and added a 4-PINS MOLEX connector in order to connect the USDC directly through the motherboard.






Male MOLEX connector :


Fixations and female MOLEX connector on motherboard :

Originally Posted by _dopehead_

coucouillu> You need to create a small circuit with a transistor and a few resistors, to power the ls-372 from an mpegbox usc20d, here is the schematic : http://www.mpegbox.net/forums/viewto...dd525874fbeb4e

I have the same combo of the ls-372 and usc20d running in my car, so it works fine with this little curcuit.

This circuit looks easier than mine.

Ya, that one you did looks a bit bit much for this, the one i did is housed inside a piece of flexhose around the power switch cable going from the motherboard to the psu.

Originally Posted by _dopehead_

Ya, that one you did looks a bit bit much for this, the one i did is housed inside a piece of flexhose around the power switch cable going from the motherboard to the psu.

Mine is integrated to the USDC.