problems with new pc build

[luvvbuzz]

i am buliding a low spec computer for my aunty, as she has an old pentium1 without internet capability. i am usinga socket 7 mother board with an amd 500mhz cpu and 128mb ram. i have installed the motherboard into the new atx case, connected up all wires as shown in motherboard manual and powered on. dead as a door nail. so i tried another case, still dead as a door nail. am i shorting the motherboard out or something or have i got a dead motherboard? the fan does not come on in either of the atx cases when i power on, indicating no power. is there any way i could find out what the fault is, like find out if its the motherboard or if i have bought 2 atx cases both with non working psu's? i find it unlikely that the 2 atx cases both have faulty psu's but i suppose i could be really unlucky. any suggestions on help would be grateful as i id really like to get my aunty online.

[flaninacupboard]

get your PSU, plug it in to the wall. look at the ATX connector, put a paperclip/wire between the green cable and a black cable. if the fan starts up, your PSU works.

if it works, plug it back into the mobo. disconnect any IDE drives. just connect your power switch and pc speaker. try turning it on. hopefully, it'll either work, or you'll hear some beeping. but whatever happens, post back and we'll try again.

[luvvbuzz]

get your PSU, plug it in to the wall. look at the ATX connector, put a paperclip/wire between the green cable and a black cable. if the fan starts up, your PSU works.

if it works, plug it back into the mobo. disconnect any IDE drives. just connect your power switch and pc speaker. try turning it on. hopefully, it'll either work, or you'll hear some beeping. but whatever happens, post back and we'll try again.

i know this is a very late reply but i have just got a new motherboard for this project which never made progress, cos i thought i had bought a dud motherboard. anyway i have set it all up and again i cannot get this to start up and the psu fan didnt even come on, so i did what u said, put a paper clip between the green and black wire on the atx connector from the psu and the fan came on when i plugged it in so the psu is working fine.
i am wondering if the switch on the atx box doesnt work, although it should it is brand new out the box, but is there a way of testing that?

[flaninacupboard]

yep

Plug your PSU into your mobo, and PSU into the wall. locate the jumper on the mobo for the power switch. take a small scredriver and short the two pins. system should spring to life.

[luvvbuzz]

ok i just discovered the problem, but now i dont know the answer to the problem. this is what i just did, i set up everything out side the atx box, connected everything up out of the box, and started it up, hey presto it works. so i would say that the back plate which the motherboard screws into and slides inside the atx case is shorting out the motherboard cos the motherboard solder points on the back are all touching the back of the back plate. my only problem is the mother board is supposed to be screwed to the back plate so that it can sit inside the atx case in the correct place/position, so how do i stop the solder points on the back of the motherboard from shorting out on this backplate?

[adam]

You can buy tiny little extensions that give your mobo a little more clearance from the backplate. They fit on the screws, insulate those, and make the mobo sit a little further out. I've seen them for sale at cyberguys.com but I'm sure any online pc parts store would have them. Very cheap.

From what I've seen this problem doesn't really happen with newer mobo's, but is common with older ones.

[flaninacupboard]

your mobo probably came with a sheet of white or pink thick foam on the back of it. you can -try- using that behind your mobo, but i think junking the case and buying a new one may be a better idea

[luvvbuzz]

can i not just use plastic washers or something?