use of Insulating Washers

[BC_Programmer]

BC, I have already read that many time. It never says the support holes are only for mechanical mounting.

Hmm, good point. I was reading the bit where it says that three new mounting holes have been added (as in since the previous specification) for mechanical support. On the other hand, the only mention of "grounding" is found in the statements about the I/O shield and why it shouldn't be painted. Nothing about the mounting screw locations having anything to do with grounding. Is that not an ATX specification? If not why does the Intel board manual not mention it either? What proof do you have that any of the actual components tie into these alleged "grounding" screws?

[/quote]

  In fact, it does not say you even have to use the holes for anything at all.

Yes it does, that is implied in the name- "Mounting" holes. You know, for mounting.

The board was, is, fabricated with  explicit  ground  points on the underside of the holes.

Document this. With documents, not pictures. If this is the way they engineered it, would they not have technical documentation about how to make sure it's properly setup and functional?

Next you will tell me that Rose bushes don't have thorns because you have never seen them.

The difference here, is there is a good reason for a Rose bush to have thorns (actually, they are technically prickles), in that it helps the rose plant grow over top of other vegetation, as well as other advantages like reducing animal browsing... in this case, there is no good reason for the "engineers" to come up with this type of non-solution. It doesn't solve a problem. There is already a ground available for the motherboard to use.

aid the rose in hanging onto other vegetation when growing over it.
[/quote]

[Geek-9pm]

hey engineered it,

I have to go to a conference n ow. I will be back later with additional information.

[Salmon Trout]

Motherboards work perfectly well out of the case, resting on e.g. a rubber mat. The "grounding" (power supply return) is provided by the black wires leading to the power connector.

[Geek-9pm]

Motherboards work perfectly well out of the case, resting on e.g. a rubber mat. The "grounding" (power supply return) is provided by the black wires leading to the power connector.

Need to clarify terms.
grounding
power supply return
Are not the same.

[BC_Programmer]

Need to clarify terms.
grounding
power supply return
Are not the same.

OK, well I think I'm done here. I've had more productive discussions with flatulence.

[Geek-9pm]

OK, well I think I'm done here. I've had more productive discussions with flatulence.

BC, You are the one making a stink.

The thread is: Re: use of Insulating Washers
My intent t is to say that they washers are not needed on many Intel motherboards.

They ones I have are explicitly fabricated and prepared for ground contact.
I did not make any statements about power supply wiring options. Not did I imply there were any other wanton connects to  the power supply.
In the industry the term grounding with reference to a PC fabrication simply means there is a point or points where it is expected that nan electrical connection be made to the case of the unit. It does not mean any power will be sent into the paint. It is for shielding.
And I never said it would not work if you did not use the ground connections. I did say it will work in a Pizza box, which is true. Not recommended. Violates FCC rules.

Is Intel wasting money on fabricated ground points on their motherboards?  I don't know, I never worked for them. I do know that when I  ordered a PC board with extra stuff on it that was not needed, my superiors had some words for me. But of course, that was ages ago.Does it no longer matter?

Maybe noways they don't care about those kind of details. Or maybe motherboards are so much more sophisticated that the old school rules don't mean a thing. Haste makes waste.. Apparently not. Everybody wants to use fiber washers where the PC board was peeped for contact. Good for the economy.The fiber washer people need to eat too.

I am doing some photos of another Intel board.

EDIT: Found this:
http://biorobots.cwru.edu/server/howto/buildcomp/mountmobo/

[BC_Programmer]

In the industry the term grounding with reference to a PC fabrication simply means there is a point or points where it is expected that nan electrical connection be made to the case of the unit. It does not mean any power will be sent into the paint. It is for shielding.

the only mention of "grounding" is found in the statements about the I/O shield and why it shouldn't be painted.

the I.O shield isn't connected to the standoffs, though. And it's for preventing interference and try to diffuse the EMI so that it doesn't cause interference.

[patio]

An argument with Geek over semantics....who'd a thunk it ? ?
I use the washers ...as i said earlier.
I used to think it just saved the time removing and re-mounting the MBoard...now i see i also saved alot of arguiing time as well...

[Geek-9pm]

the I.O shield isn't connected to the standoffs, though.

It is on the Intel boards I have. Is it not one yours? 

[Geek-9pm]

Here is a photo from the backside of an Intel motherboard I have in my shop. This motherboard is in good condition, works fine, inside a box or a, rounded to the case or not.


If you want to see more photos of this motherboard here is a link that takes you to a folder on my site and you can click on any picture you want to see. I have not put the pictures here on computer Hope. They are quite large and will suck bandwidth. I have leftover bandwidth on my site, mostly because nobody ever goes there.
http://geek9pm.com/pads/

[lectrocrew]

Easy to test for yourself.  Place an ohmmeter between 2 mounting holes.

Good idea. And I did. And the results suprised me. Testing between all mounting locations on my Intel D845GVSR yeilded a result of "0" ohms resistance on 20k DVOM scale between all mounting locations. I don't see where they are connected to the circuit traces, but they are certainly connected somehow. I'm certainly curious as to what significance this has as far as operation. I guess my next test will be running the mboard in a pizza box. Seriously! Thanks for the test idea Geek-9pm.  I'll post the results later.

When changing Motherboards I often see that there has been a lot of effort put into putting red insulating washers on all the mounting holes. Is there a good reason for doing this ? And if it is necessary why don't the manufactures use bushes in the holes.

Thanks

Good thread! 
Did you mean bushings rather than bushes? 

[lectrocrew]

ground plane (internal),

'Multi layer'. I guess this would explain the 0 ohms resistance between mounting points without visual evidence of a trace connecting them. 

[Salmon Trout]

Did you mean bushings rather than bushes?

In this context the words are synonymous. A bush is a hollow cylinder. A bushing is a hollow insulating liner through which a conductor may pass.

[BC_Programmer]

Here is a photo from the backside of an Intel motherboard I have in my shop. This motherboard is in good condition, works fine, inside a box or a, rounded to the case or not.

Searching for relevance...

NOT FOUND.

You claimed:

the entire common return of the entire board, memory, PCI, CPU, I/I ports, including USB. the whole thing.

And yet you just said that you weren't talking about the return circuit, and suddenly you try to retrospectively change your goalposts to (and I'm paraphrasing) "oh I was totally talking about that EMI thing you already mentioned". But you said yourself that it is the common return of the entire board? there is no electrical connection between the mounting holes and any electrically active traces, so how you come to that conclusion I cannot guess.

If you want to see more photos of this motherboard here

Why would I want to do that? I'm not even sure what they are supposed to "prove" or disprove.

Testing between all mounting locations on my Intel D845GVSR yeilded a result of "0" ohms resistance on 20k DVOM scale between all mounting locations. I don't see where they are connected to the circuit traces, but they are certainly connected somehow.

The mounting holes will be conducive through the case.. unless it's plastic, I guess. as Salmon Trout corrected me with respect to the mounting standoffs,all metals conduct electricity.  Testing on a unused AMD board I have and there is no connection between any of the mount points. Of course that was an AMD board, which no doubt will serve to fuel some additional rhetoric by Geek-9pm. Of course I'm no longer questioning whether there is any resistance between them but rather that there is no electrical connection between the mounting holes and the board traces, as he alleged earlier by saying that the mount points serve as "the entire common return of the entire board, memory, PCI, CPU, I/O ports, including USB. the whole thing." Which is both nonsensical, plain wrong, and he has yet to provide any sort of evidence aside from a few pictures of the board... which are utterly meaningless.

[patio]

See my Post above...