I made a system by myself with an abit p35 pro.
Well, if i just touch/push the motherboard the pc turns off.
Of course something going on with the case(which is old)
Question: the holes that the mobo has are GROUND?
They should be in touch (electrically) with the case?
Thats what i have done. I dont speak english well but i can describe that the screws (and the mobo) are in direct contact with the metal case
If i use my pc out of the case (the parts on the table)i have no problem, so...where should i look at?
You should have the holes lined up with the standoffs. No extra standoffs under the board that aren't in line with a hole. I always use the brass ones, even with cases that have built in standoff mounds. What power supply do you use- brand and wattage?
It seems very likely that some part of the underside of the motherboard is touching the bottom of the case and causing a short when you move it. Make sure no part of the case under the motherboard is sticking up and touching it. Probably your best bet would be to try longer standoffs. Also be sure to use a standoff and screw at every mounting hole on the motherboard. This will help reduce bending of the motherboard, which could casue it to short to the case.
I would get and use a standoff at every mount point.
Another possible location for a short is the front edge of your mobo where the PCI brackets are. A strip of electrical tape along the front edge of the mobo will address this possibility, if the standoffs alone are not sufficient.
Thats what they look like (the bottom surface is the case). They (all metal)have a hole in the middle. I put the mobo on them and the use the screws.
If I understand correctly, you have the chrome colored clip style standoffs pre-mounted in the bottom of the case. I have seen this style before. The issue is that they may be larger in diameter than the protection ring around the MB hole, and therefore, maybe contacting an electrical trace on the MB.
At any rate, the best way to fix this is to put a piece of electrical tape over each of these so that it covers the entire standoff. Then use a toothpick or similar sharp object to poke a hole in the middle so the screw can go through. reinstall the MB and screw it down. Also make sure the head of the screws you are using stays inside the protection ring on top. If you have any of the red cardboard washers that come with some kits, use this as well with the screw.
By the way, your MB gets "grounded" through the power supply connectors. The standoffs can cause a "short".
Well, i remember that by using a multimeter i found out that the holes and the metal "boxes" that have the usb,soundcard etc connectors at the back of the mobo are short wired.
If thats the case, doesnt that indicate that the holes are GROUND?