What causes a mobo 'short' ?

Brizzles · 30 Jan 2010 at 22:21

As title, what causes a 'short' ?

Recommendation for fault finding is build outside the case on a non-conductive surface.

But if that cures it how do i prevent it from reoccuring when its put back in.

But what am i looking for on the mobo ?

Solder points touching the mounting tray ?

Any clues

Cheers,

Mark

alex24 · 30 Jan 2010 at 22:27

Usually it's to do with the wrong/no motherboard standoffs being used in the case. Check that they're present, and if it's an ATX, MATX, EATX board, that they're in the right position, usually marked on the motherboard tray. You can also check by just aligning the board with the tray.

Brizzles · 30 Jan 2010 at 22:36

Would it make any difference if just 1 stand-off is missing ?

TheRedZealot · 30 Jan 2010 at 23:07

If the board is bowing towards the tray or if there is any contact at all between board and tray it would more than likely cause it to short.

setter · 30 Jan 2010 at 23:37

mrdbristol said:
Would it make any difference if just 1 stand-off is missing ?

I once installed a board and forgot one stand off, worked fine though.

richb93 · 30 Jan 2010 at 23:48

It would make a difference if a standoff is in the wrong point and then it would short the ground to the point on the board above it.

Brizzles · 30 Jan 2010 at 23:48

TheRedZealot said:
If the board is bowing towards the tray or if there is any contact at all between board and tray it would more than likely cause it to short.

Could be.

I know the backing plate from the cpu waterblock touches the tray.

Makhaira · 30 Jan 2010 at 23:52

3 things to check for really.

1) Make sure that the number of standoffs screwed into the tray equals the number of screws that you have then put through the motherboard into the standoffs. Most common error is to have an extra standoff pressing against the board.

2) Check the backplate to ensure that the clips are not shorting on anything. They shouldn't, but sometimes they can get bent and cause issues.

3) Check for shorts with a heatsink backplate (as you mentioned above). The backplate itself should be insulated on the board-facing side though, which means it is then irrelevant if the backplate itself touches the tray.

What symptoms are you getting? What have you tried so far?