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Complete Idiots Guide to Motherboards for Dummies

I'm installed a brandnew motherboard into a brandnew case.  Something I haven't done for a long while.  The case comes with all these little cardboard washers that are obviously meant to be used with some of the screws, but which ones?  I've got 12 washers, but there isn't a type of screw that I've got that came in 12 (or 6 for that matter).

Too Dumb
Thursday, March 25, 2004

Unlike when trying to repair a car it is ok to have parts left over when you are done... :)  As long as the MB is in the case securely and nothing is shorted out then extra parts aren't a problem.

Ray
Thursday, March 25, 2004

From what I understand those washers are to insulate the screw heads from your motherboard.

If you used screws to attach the motherboard to the case, those should go on either side of the screw so as to not create a ground to the case.  I think.  In the least, it won't hurt anything by adding them, and that's what I did last time I built my own PC.

Come to think of it, the one before it didn't have them, and it lasted just fine until it caught fire.  So your mileage may vary. :)

MR
Thursday, March 25, 2004

MR is right that they're for insulting the screws that connect the MB to the case. However, you only use them if needed. Most motherboards have plenty of space to prevent any shorts there. Having them left-over is just fine.

Brad Wilson (dotnetguy.techieswithcats.com)
Thursday, March 25, 2004

What exactly do you have against screws?

Russell Thackston
Thursday, March 25, 2004

That's kinda what I was figuring.  However
1. The holes in the motherboard to screw it to the case have solder all around them both top and bottom, as if the motherboard is SUPPOSED to be grounded to the case.
2. If you were to use the washed to insulate the motherboard, you'd need to put them on both above and below the board.  Above is easy, but below (I've tried), you balance them on their little posts, place the motherboard carefully ontop, and at least half slide off.

Too Dumb
Thursday, March 25, 2004

That's why people pay Dell the big bucks. :)

MR
Thursday, March 25, 2004

My understanding is that most motherboards USE the mounting screws to ground the mb to the case.

If the motherboard had come with the washers I would want to be sure to use them.  Since you say that they came with the case I would consider them optional at least, and more likely a Bad Idea.  But the real answer is to read the mb documentation.

RH
Thursday, March 25, 2004

The motherboard should not be in contact with the case.  There are 3 parts used to mount the motherboard: screws, washers, and spacers.  The spacers may be built-in to the case or they may be separate.  The spacers are basically an elongated bolt with a "male" screw at one end and a "female" at the other.  This is used to hold the motherboard away from the metal case so it doesn't short

The washers are probably not necessary, most motherboards these days have space around the screw holes so the screw won't contact anything.  But if it looks like there might be something there go ahead and use them, they won't hurt anything

MikeMcNertney
Thursday, March 25, 2004

Does it boot?

If yes, don't worry about it

If no, then put the washers in.

pdq
Thursday, March 25, 2004

The mounting holes in motherboards seem to be plated in order to make contact with the screw head.  I'm looking at an old Gigabyte motherboard and every mounting hole is plated.

If a path to the case & ground were not desired, then there would be no plating around these holes, instead there would be bare PC board.

The only "insulation" that seems to make sense is the necessary spacing between the soldered points on the bottom of the mobo and the case.

Bored Bystander
Thursday, March 25, 2004

The motherboard has a perfectly good from the power supply. It doesn't need to rely on screws and stand-offs to be grounded.

Brad Wilson (dotnetguy.techieswithcats.com)
Friday, March 26, 2004

I did a bit of checking, and if the screw head touches any leads on the motherboard (very unlikely) then you have to use a washer because it would most likely short out the motherboard.  Most manufacturers nowadays put the holes in a way that they are far away from leads so provided you use a standard computer screw you are fine -- the only way it could be a problem is if you use some sort of ridiculous coin-sized screw-heads.

The metal ring around the screw hole is to prevent the screw head from catching on the PCB and damaging the board.  I suspect it also might be a slight reinforcement measure against overtightening, too.

MR
Friday, March 26, 2004

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