[Shootist]

I've heard that some people use paper (maybe even rubber) washers when attaching to the case.

Thoughts?

[Dice]

I have never used one. Never been a problem.

[eobard]

I would be surprised if I've installed less than 100 mobo's in cases, sometimes with washers, sometimes without, and I have found that not using washers has prevented some systems from booting BUT, to my best recollection I haven't NEEDED to use them since the 486 days. Just to be safe I put washers both on top of and beneath the mobo. The top ones are easy to deal with, to keep the bottom ones on the standoffs I just use a bit of glue. Maybe it's not needed but they invented the "ounce of prevention" proverb for a reason right?

[mbigna]

Don't use washers unless you absolutely have to in order to keep a trace that is too close to the screw from becoming scratched and inadvertently grounded.

This is only a problem with older boards as the new boards route critical traces far from the mounting points to avoid this problem now. New boards are now manufactured to intentionally ground the board at the mounting points. It is more a problem if your board is NOT properly grounded these days.

If you look at most new boards now, you can see wide solder points that are there to intentionally contact the screws in order to ensure proper grounding.

[JDXNC]

I haven't used them in years, only found they were needed in some older boards that had traces too close to the mounting holes. Every board I have dealt with in the last 5'ish years has not needed them.

[=ACID RAIN=]

Same. I used them when I overlapped traces, which basically doesn't happen nowadays. Those metal rings around the holes are connected to the ground plane for a reason

[Shiggity]

Like this?



That guy used rubber stoppers for insulation then taped the backs with electrical tape so it couldn't ground to the bottom of the case.

http://www.xtremesystems.org/forums/...&postcount=751

He was doing something different than what you want, but the principal is essentially the same.

[mbigna]

Shiggity--

The pics you show are for mounting HEATSINKS, NOT for mounting to the case.

The holes for mounting modded heatsinks/fans are usually secured with plastic expansion pins rather than metal screws. It seems that this person wanted a heavy-duty/tight mount, so he decided to use metal screws and insulated the mounts accordingly.

If you look at the other pictures in your link, you will see each of the case mounting holes have 8 solder points around each of them. It is advisable NOT to insulate those from the case screws/mounts. They should be intentionally grounded to the case.

[eobard]

Everyone else is saying to not use washers but I've never had a problem with them. I understand the point about not interfering with proper grounding but there are grounds in the cables going to and coming from the mobo, there are grounds everywhere in the system, and they all come together eventually (or whoever designed the mobo isn't doing their job). Just now I did a google for pics of clear acrylic/lexan cases and while some have metal base plates a lot don't. And how many people have made home-made wooden cases without screwing the mobo into a metal base? Do a search of the Alternative Modding section of these forums alone for wood cases and you'll see quite a few without metal backing behind the mobo. Now I'm not saying you should put washers in and not ground to the case through the mobo standoffs, that choice is yours and yours alone to make. But I've not had any problems using them myself. As I said before I haven't had any issues related to grounding the mobo since the original Pentium came into existence, so I don't think you have too much to worry about either way.

[iansmith]

You should never isolate the motherboard

Motherboards have extremely delicate signals traveling over large distances with exact timings, and propper grounding is part of the design. I have done circuit board designs and things on motherboards are where they are for a reason. All ground has to come together eventually (or it's not grounded!) but having multiple paths is important in something as critical, large and compilcated as a motherboard.

Using washers on a motherboard isn't going to make it explode when you turn it on, just like smoking will not cause a tumor to grow out of your chest after the third puff. But not grounding your motherboard will greatly increase the chances of something going wrong, so why risk it?

[Shootist]

Great info. Thanks guys.