Quick question: standoffs/washers

[rileychris]

I have a silverstone Tj05. It came with brass standoofs, screws and what looks like red paper washers. Do I use these washers? Do they go on top of the MB to separate the screws from the board?

Thanks in advance,

rc

 

[joelslaw]

I've built quite a few systems and never have understood what they are for. I just don't screw whith them. (no pun intended)

 

[Viperoni]

They're purpose is to isolate the backside of the MB from the actual standoff... but it's pointless because the MB still grounds through the top side of the MB -> screw -> standoff...

 

[joelslaw]

Originally posted by: Viperoni
They're purpose is to isolate the backside of the MB from the actual standoff... but it's pointless because the MB still grounds through the top side of the MB -> screw -> standoff...

then why do they still send them with, mobo's, cases, etc? that's stupid! maybe they don't understand how electricity works

kind of reminds me of your sig (which is pure genius by the way. stupid ppl comeing to get me........ that'll give me nightmares!)

 

[lenjack]

Viperoni...it doesn't. If you look closely, you'll see that the metal ring around the hole does not contact any other part of the circuitry. The metal ring is not there for electrical reasons, it's there to reinforce the hole. As to the original question, the washers are not needed. Don't know why they are even included these days.

 

[joelslaw]

acctually, I think he's right. Of corse it doesn't touch the circuitry, that would ground all the mobo signals (ie. your pc wouldn't work) but I think it does ground the static. (mobo > screws > standoffs > chasis > PSU > ground plug > wall jack)

 

[Peter]

The metal ring around the holes is there to connect to frame ground alright. You might not see a connection on the outside layers (which are typically used for signal traces), but there might be on the inner layers you don't see.

The rule is: Blank ring around mounting hole -> no washer. No ring -> washers top and bottom. With ATX boards, the latter case rarely happens anyway. BAT was more "fun".

 

[ahurtt]

A funny thing though. . .on a couple systems I built that came with those little red insulating washers, they only provided enough of them to go on either the top of the motherboard (under the screw head) or the top of the standoff (under the motherboard). They didn't provide enough to put one on both sides of each hole. I didn't use them anyway because I determined I didn't need them upon examining the mounting holes on the board. But how come they only gave enough to put on one side or the other?

 

[Zepper]

The mobo mounting holes are plated thru-holes connected to the ground plane - an ohmmeter can prove that to you.
. The washers go under the screw heads - trying to use them on the back side of the mobo is an exercise in futility (unless you want to go to the bother of gluing them to the back of the board or the top of the standoffs).
. My theory is that they are to allow for thermal cycling (expansion-contraction during heating and cooling) and to help reduce over-tightening (can crush the board if not careful). In the old days only one or two mounting points were the fixed post and screw type. The rest were snap-in nylon standoffs which had plenty of give for thermal cycling - I still use modified nylon standoffs for extra support. Now that most mount points are of the post and screw type, I consider using the washers (if you have them) to be a good practice.
.bh.

 

[rileychris]

At about 1:00 last night I successfully booted my first DIY PC. I decided to go without the washers. Thanks for all of the help guys! I am sure I will have more questiosn as I try to add in more components and hook up all the front panel stuff.

 

[joelslaw]

congrats! and welcome to the area

 

[CraigRT]

I never use them, ever