Re: PC is dead after installing new board

Only one standoff must connect motherboard ground to chassis
ground. Intel specs for PCs put numerical specs to area in
which this connection (conductive standoff) should be
located. It is typically the standoff hole between IO card
slots and power supply connector. Another permitted standoff
was located in the PCI slot region.

Why only one ground? Currents do conduct across the chassis
plate. If motherboard is grounded to chassis in multiple
locations, the currents would also flow through motherboard
ground plane creating voltage differences (noise) between IC
on that motherboard. We would demonstrate this problem by
putting a computer on a glass table and static electric
shocking the chassis. That static electric discharge (that
flow across motherboard with multiple conductive standoffs)
would cause the OS to crash. Better computer stability means
only one path exists between computer motherboard and chassis
plate. With only one connection (without both an incoming and
outgoing path through motherboard), then electric currents in
a chassis do not pass through motherboard.

Bob H wrote:
> Can you tell me what a single point ground is in realtion to a
> motherboard? Does it mean only one connection/standoff should
> be ground?
> Thanks
.

Relevant Pages

  • Re: Really stumped: PS inoperative
    ... Best connection between a motherboard and chassis is only at one ... that fiberglass board is not damaged by a tightened standoff. ... standoff contacts a PC trace, ...
    (comp.sys.ibm.pc.hardware.misc)
  • Re: PC is dead after installing new board
    ... Intel specs for PCs put numerical specs to area in which this connection (conductive standoff) should be located. ... If motherboard is grounded to chassis in multiple locations, the currents would also flow through motherboard ground plane creating voltage differences between IC on that motherboard. ... With only one connection, then electric currents in a chassis do not pass through motherboard. ...
    (alt.comp.hardware.pc-homebuilt)
  • Re: Using xp coa of dead pc on new pc
    ... Except that the sticker is stuck onto the chassis. ... replacements in Dell chassis with a Dell motherboard, of course, reloaded ... Using xp coa of dead pc on new pc ...
    (alt.sys.pc-clone.dell)
  • Re: Pavillion
    ... installing it in an external USB housing. ... >From what little I have been able to glean from HP's web site, the chassis takes ... others may debate the issue of motherboard quality. ... Replacing the system and installing the old drive in the replacement computer is ...
    (comp.sys.hp.hardware)
  • Re: Choosing a Motherboard (for a Linux machine)
    ... >> motherboard. ... If, however, you want something that will fit in a stereo ... I thought that the microATX was smaller, ... > a chassis be optimized for a CPU? ...
    (comp.os.linux.hardware)