In a message dated 11/7/98 7:27:04 AM Eastern Standard Time, [log in to unmask]
writes:

<< Hello all,
 The question I am about to ask may seem pretty elementary to some of you
 but I cannot sem to find an answer from any other resource. When mounting
 a motherboard, as you know there are several holes for placing the
 mounting screws. Around each hole is a solder coating. When should the
 little red plastic washers be used and when not. Does the procedure
 differ from AT to ATX? I have an ATX Gigabyte GA5AX512 Mobo which I have
 mounted using the red plastic washers on all screws with no problems.
 Some info on this would be helpful. The manual says nothing about it. I
 have also searched "Upgrading and Repairing PC's" and "Tom's Hardware
 Guide" Web site with no luck. Thanks. >>

Hi,
  The motherboard uses 2 types of grounding. The first is the DC power ground
(the only one it absolutely needs), which it gets from the wires in the power
supply connectors that plug into the motherboard. The second type of grounding
it gets is RFI (Radio Frequency Interference) grounding. This is to help
minimize RF emissions of the computer, affecting nearby radios, TVs, etc. This
is accomplished by grounding the motherboard to the metal chassis (case),
through the mounting screw(s).
  As long as there is enough clearance between the standoffs (spacers)
underneath the motherboard, and any of the copper signal traces on the
motherboard, (and the same with the screwheads on the top), there is no need
to use the washers. If on any hole, the traces come too close to the mounting
hardware, where they might be accidentally grounded by the standoff or the
screwhead, then the insulating washer must be used to prevent this.

Hope this helps,
Peter Hogan
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