|First of all thanks for your asnwer,|
I can't see any visible or as you said obviuos damage in the motherboard, regarding disconnecting all the drives, I already did that, but it didn't work, well, in fact I also discconnected the video card, and all the RAM modules, hopping to at least see any other evidence of life when powering it up, but no, it was the same, only the fan and the CD Rom led are working, (do you think I should try to do it with the video card on?, I will try that way).
Oh, and by the way, there are no beeps in any startup.
There's other thing, when I connect once again the usb header in the wrong position (rotating the connector upside down) and I power up the system, all the CD roms, along with the power on light on the front panel lights up, I guess is telling me that the connection is wrong.
In the case that I broke the motherboard with this, do you think that is more expensive try to fix it, rhater than buying a new one?
Is an old model, Shutter AB30 mother board...
Thanks for your comments.