insulators needed under mobo's mounting screws?

Thanks ! Some other people have suggested that the
paper-washers-on-mounting-screw thing dates back to AT Power Supply days.

FYO:
((The old motherboard was an AOpen MX6E PLUS which has an Intel 440EX
chipset. ))
((The new one is an Asus P2B-F which has an Intel BX chipset.))

But now I have a different problem: I have printed off the 80 page PDF
manual from Asus's site ... and have installed the motherboard; set the
jumpers to the proper bus speed and multiplier; installed the CPU and 2
sticks of memory (128mB total) ; installed just one card - the PCI video
card; connected the PS power plug to the mobo ...and hooked up most of the
control leads like reset, power SW leads to mobo, speaker, etc. leads. But
what happens when I turn on the Power Supply's switch (at the back) is the
following:

- unit powers up without waiting for me to press the power-on button on the
front of the tower
- Keyboard's 3 lights flash once on momentarily
- no beep or anything from speaker
- CPU fan operates.
- nothing shows on the monitor ... it's green LED continues to flash from
time to time like it is in sleep mode.

Based on the above symptoms, what is the general consensus as to what is
wrong?

Thanks !

-RS-


"sooky grumper" <sookygrumper.RemoveThis@fishies_.com> wrote in message
news:40a66b62$1@quokka.wn.com.au...
 > RS wrote:
  > > I am repairing a computer that has a AOpen Slot 1 motherboard that won't
  > > boot. (The CPU tests OK on another system, as does the RAM)
  > >
  > > I have purchased a used ASUS Slot 1 motherboard off of eBay. I am now in
the
  > > process of swapping the motherboards and I see that the old motherboard
has
  > > pieces of black electrical tape on the bottom where the mounting screws
poke
  > > through. Is this necessary?
 >
 > no
 >
  > > I know that bags of hardware that comes with
  > > computer cases used to (I recall) include little brown "paper" washers.
  > >
  > > Thanks for any knowledgeable opinions / clarification !
  > >
  > > -RS-
  > >
  > >
 >
 >
 > --
 > spammage trappage: replace fishies_ with yahoo<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

On Sun, 16 May 2004 03:11:36 +0800, sooky grumper
<sookygrumper DeleteThis @fishies_.com> wrote:

 >RS wrote:
  >> I am repairing a computer that has a AOpen Slot 1 motherboard that won't
  >> boot. (The CPU tests OK on another system, as does the RAM)
  >>
  >> I have purchased a used ASUS Slot 1 motherboard off of eBay. I am now in the
  >> process of swapping the motherboards and I see that the old motherboard has
  >> pieces of black electrical tape on the bottom where the mounting screws poke
  >> through. Is this necessary?
 >
 >no
 >
  >> I know that bags of hardware that comes with
  >> computer cases used to (I recall) include little brown "paper" washers.
  >>
  >> Thanks for any knowledgeable opinions / clarification !
  >>
  >> -RS-
  >>
  >>
You can use nylon flat washers as insulators.
The better computer shops sell hardware packs that have these neat
little nylon standup spacers with insulator sleeves that can isolate
the board from the metal of the chassis.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

gothika wrote:

 > On Sun, 16 May 2004 03:11:36 +0800, sooky grumper
 > <sookygrumper.RemoveThis@fishies_.com> wrote:
 >
  >>RS wrote:
   >>> I am repairing a computer that has a AOpen Slot 1 motherboard that won't
   >>> boot. (The CPU tests OK on another system, as does the RAM)
   >>>
   >>> I have purchased a used ASUS Slot 1 motherboard off of eBay. I am now in
   >>> the process of swapping the motherboards and I see that the old
   >>> motherboard has pieces of black electrical tape on the bottom where the
   >>> mounting screws poke through. Is this necessary?
  >>
  >>no
  >>
   >>> I know that bags of hardware that comes with
   >>> computer cases used to (I recall) include little brown "paper" washers.
   >>>
   >>> Thanks for any knowledgeable opinions / clarification !
   >>>
   >>> -RS-
   >>>
   >>>
 > You can use nylon flat washers as insulators.
 > The better computer shops sell hardware packs that have these neat
 > little nylon standup spacers with insulator sleeves that can isolate
 > the board from the metal of the chassis.


Why would you do that? Just wondering....
--

Stacey<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

RS wrote:
 > Thanks ! Some other people have suggested that the
 > paper-washers-on-mounting-screw thing dates back to AT Power Supply days.
 >
 > FYO:
 > ((The old motherboard was an AOpen MX6E PLUS which has an Intel 440EX
 > chipset. ))
Are you ABSOLUTELY SURE that the Aopen power supply has the standard
wiring, and is in good order, meeting PC specifications? (Some
proprietary Power Supplies, such as Compaq, switch around the wiring!
Not sure about Aopen, but, I had tried to switch out an Aopen board,
with another brand mainboard, and ended up getting a new case and PSU,
before the computer would work!).
 > ((The new one is an Asus P2B-F which has an Intel BX chipset.))

Did you pull the bios battery, so that the CMOS resets to factory specs.?
Incorrect CPU settings in CMOS can conflict with board jumpers so that
nothing comes up, clock never starts.

 > But now I have a different problem: I have printed off the 80 page PDF
 > manual from Asus's site ... and have installed the motherboard; set the
 > jumpers to the proper bus speed and multiplier; installed the CPU and 2
 > sticks of memory (128mB total)
Try it with only minimal memory, in only one DIMM slot.
Make sure it meets the speed requirements (100 Mhz?)


; installed just one card - the PCI video
 > card;
If it has an AGP slot, do NOT install the PCI video card in the adjacent
PCI slot (sometimes 'shared' with AGP).



 > connected the PS power plug to the mobo
Plug it in very firmly, make sure it is not cocked...
...and hooked up most of the
 > control leads like reset, power SW leads to mobo, speaker, etc. leads.

Double check all the connections...
 > But what happens when I turn on the Power Supply's switch (at the back) is the
 > following:
 >
 > - unit powers up without waiting for me to press the power-on button on the
 > front of the tower
 > - Keyboard's 3 lights flash once on momentarily
 > - no beep or anything from speaker
 > - CPU fan operates.
You have the 12Volts, (fan on board) but, evidently, NOT the 5 Volts
that mostly powers the CPU, system clock,PCI bridge (SouthBridge) and
Memory, Voltage regulators.
Have four of that ASUS mainboard here, plus two each P2B-DS,
P2L97-DS266, CUV-4DS boards. Very hardy stuff, very reliable!
 > - nothing shows on the monitor ... it's green LED continues to flash from
 > time to time like it is in sleep mode.
 >
 > Based on the above symptoms, what is the general consensus as to what is
 > wrong?
 >
 > Thanks !
 >
 > -RS-
 >
 >
 > "sooky grumper" <sookygrumper.DeleteThis@fishies_.com> wrote in message
 > news:40a66b62$1@quokka.wn.com.au...
 >
  >>RS wrote:
  >>
   >>>I am repairing a computer that has a AOpen Slot 1 motherboard that won't
   >>>boot. (The CPU tests OK on another system, as does the RAM)
   >>>
   >>>I have purchased a used ASUS Slot 1 motherboard off of eBay. I am now in
 >
 > the
 >
   >>>process of swapping the motherboards and I see that the old motherboard
 >
 > has
 >
   >>>pieces of black electrical tape on the bottom where the mounting screws
 >
 > poke
 >
   >>>through. Is this necessary?
  >>
  >>no
  >>
  >>
   >>>I know that bags of hardware that comes with
   >>>computer cases used to (I recall) include little brown "paper" washers.
   >>>
   >>>Thanks for any knowledgeable opinions / clarification !
   >>>
   >>>-RS-
   >>>
   >>>
  >>
  >>
  >>--
  >>spammage trappage: replace fishies_ with yahoo
 >
 >
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

gothika <Vampyres.DeleteThis@nettaxi.com> wrote in message news:<66pda05vcjt2mv58ec4j9gumui48e1nevt.DeleteThis@4ax.com>...

 > You can use nylon flat washers as insulators.
 > The better computer shops sell hardware packs that have
 > these neat little nylon standup spacers with insulator
 > sleeves that can isolate the board from the metal of the
 > chassis.

That hardware is also available from electronic supplies and hardware
stores (smaller ones, not home centers), often for less than computer
store prices. I'm not sure what nylon standup spacers with insulator
sleeves are, but there are nylon standoffs made for circuit boards,
and most snap into the board. Nylon hex spacers are also available
with threaded holes, and nylon screws can be used with them.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

gothika <Vampyres.TakeThisOut@nettaxi.com> wrote in message news:<66pda05vcjt2mv58ec4j9gumui48e1nevt.TakeThisOut@4ax.com>...

 > You can use nylon flat washers as insulators.
 > The better computer shops sell hardware packs that have
 > these neat little nylon standup spacers with insulator
 > sleeves that can isolate the board from the metal of the
 > chassis.

That hardware is also available from electronic supplies and hardware
stores (smaller ones, not home centers), often for less than computer
store prices. I'm not sure what nylon standup spacers with insulator
sleeves are, but there are nylon standoffs made for circuit boards,
and most snap into the board. Nylon hex spacers are also available
with threaded holes, and nylon screws can be used with them.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

"RS" <jf_reneX.DeleteThis@Xhotmail.com> wrote in message news:<vktpc.9713$RM.6221@edtnps89>...

 > I am repairing a computer that has a AOpen Slot 1 motherboard
 > that won't boot. (The CPU tests OK on another system, as does
 > the RAM)
 >
 > I have purchased a used ASUS Slot 1 motherboard off of eBay.
 > I am now in the process of swapping the motherboards and I see
 > that the old motherboard has pieces of black electrical tape
 > on the bottom where the mounting screws poke through. Is
 > this necessary? I know that bags of hardware that comes with
 > computer cases used to (I recall) include little brown "paper"
 > washers.

I believe the AOpen motherboard, which, by the way, does use a
standard ATX power connector, not a proprietary one, was installed
improperly by the previous owner because electrical tape is a poor
insulator when exposed to high pressure (such as from motherboard
mounting screws) or sharp edges (such as from screws or brass standoff
posts), and it may have gradually been pierced and shorted the
motherboard to the chassis. Those brown paper washers are much better
for this application, as are Mylar washers (translucent, creamy white
or yellow only, not the much thinner transparent ones) and the nylon
washers mentioned by Gothika.

Motherboards are supposed to be designed so they cannot possibly short
to the chassis, whether or not insulator washers are used, but in
reality this isn't always so, and I've seen holes where copper signal
traces or even large copper areas connected directly to a power supply
voltage ran close enough to cause shorts. Therefore you must inspect
each mounting hole and not make any assumptions. If a hole has a
copper ring around it (that copper is usually coated with solder) or
has no metal within at least 1/8" - 3/16" of its circumference, then
no insulator washer is needed -- for that particular side of the hole.
When in doubt, install an insulator because it won't do any harm,
unlike a short.

Older computers did not use stamped risers (raised dimples) for
mounting the motherboard but instead had brass mounting posts screwed
to them from the bottom or rails spot welded in place with slots into
which nylon standoffs could slide. Stamped risers weren't introduced
in computer cases until they became cheapened and made of thinner
metal, but even brass mounting posts, despite being narrower than
risers, still often need insulator washers on them.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

"RS" <jf_reneX.TakeThisOut@Xhotmail.com> wrote in message news:<vktpc.9713$RM.6221@edtnps89>...

 > I am repairing a computer that has a AOpen Slot 1 motherboard
 > that won't boot. (The CPU tests OK on another system, as does
 > the RAM)
 >
 > I have purchased a used ASUS Slot 1 motherboard off of eBay.
 > I am now in the process of swapping the motherboards and I see
 > that the old motherboard has pieces of black electrical tape
 > on the bottom where the mounting screws poke through. Is
 > this necessary? I know that bags of hardware that comes with
 > computer cases used to (I recall) include little brown "paper"
 > washers.

I believe the AOpen motherboard, which, by the way, does use a
standard ATX power connector, not a proprietary one, was installed
improperly by the previous owner because electrical tape is a poor
insulator when exposed to high pressure (such as from motherboard
mounting screws) or sharp edges (such as from screws or brass standoff
posts), and it may have gradually been pierced and shorted the
motherboard to the chassis. Those brown paper washers are much better
for this application, as are Mylar washers (translucent, creamy white
or yellow only, not the much thinner transparent ones) and the nylon
washers mentioned by Gothika.

Motherboards are supposed to be designed so they cannot possibly short
to the chassis, whether or not insulator washers are used, but in
reality this isn't always so, and I've seen holes where copper signal
traces or even large copper areas connected directly to a power supply
voltage ran close enough to cause shorts. Therefore you must inspect
each mounting hole and not make any assumptions. If a hole has a
copper ring around it (that copper is usually coated with solder) or
has no metal within at least 1/8" - 3/16" of its circumference, then
no insulator washer is needed -- for that particular side of the hole.
When in doubt, install an insulator because it won't do any harm,
unlike a short.

Older computers did not use stamped risers (raised dimples) for
mounting the motherboard but instead had brass mounting posts screwed
to them from the bottom or rails spot welded in place with slots into
which nylon standoffs could slide. Stamped risers weren't introduced
in computer cases until they became cheapened and made of thinner
metal, but even brass mounting posts, despite being narrower than
risers, still often need insulator washers on them.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

RS wrote:
 > I am repairing a computer that has a AOpen Slot 1 motherboard that won't
 > boot. (The CPU tests OK on another system, as does the RAM)
 >
 > I have purchased a used ASUS Slot 1 motherboard off of eBay. I am now in the
 > process of swapping the motherboards and I see that the old motherboard has
 > pieces of black electrical tape on the bottom where the mounting screws poke
 > through. Is this necessary? I know that bags of hardware that comes with
 > computer cases used to (I recall) include little brown "paper" washers.
 >
 > Thanks for any knowledgeable opinions / clarification !
 >
 > -RS-
 >
 >

Why would mobo makers put metal circles around the mobo screw holes if
they didn't want the mobo to be grounded to the chassis?<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

Matt <matt RemoveThis @themattfella.zzzz.com> wrote in message news:<NdTpc.5098$PQ3.426@news01.roc.ny>...

 > Why would mobo makers put metal circles around the mobo screw
 > holes if they didn't want the mobo to be grounded to the chassis?

The problem is motherboard makers don't always put metal circles
around every screw hole, and it's possible to short the board at such
holes. So each hole has to be checked on top and bottom for either
this or, if the hole doesn't have a metal circle, for sufficient
clearance between the hole and the closest copper, which may be
carrying a signal or voltage supply. When in doubt, insulate, and
rely upon the motherboard power connector(s) and plug-in card rear
brackets for rounding.

Electrical tape makes a poor insulating material because a screw or
mounting post can easily pierce it. Satisfactory insulator washers
are made of cardboard (fiber), nylon, or Mylar (Mylar must be
translucent, not so thin that it's transparent).<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

On Sun, 16 May 2004 23:57:33 GMT, Matt <matt.DeleteThis@themattfella.zzzz.com> wrote:

 >RS wrote:
  >> I am repairing a computer that has a AOpen Slot 1 motherboard that won't
  >> boot. (The CPU tests OK on another system, as does the RAM)
  >>
  >> I have purchased a used ASUS Slot 1 motherboard off of eBay. I am now in the
  >> process of swapping the motherboards and I see that the old motherboard has
  >> pieces of black electrical tape on the bottom where the mounting screws poke
  >> through. Is this necessary? I know that bags of hardware that comes with
  >> computer cases used to (I recall) include little brown "paper" washers.
  >>
  >> Thanks for any knowledgeable opinions / clarification !
  >>
  >> -RS-
  >>
 >
 >Why would mobo makers put metal circles around the mobo screw holes if
 >they didn't want the mobo to be grounded to the chassis?
 >
The little metal circles, sometimes with solder blobs on them are of course to ground
that part, and only that part to the chassis. The spacer part of it comes in to play to make
sure that everything else on the backside of the MB doesn't ground out too.

I believe the little fiber washers mostly came into play back when the mounts on the
chassis for the motherboard were raised dimples. They were wider than they needed
to be, and the MB manufacturers were occasionally a little more.... freehanded mounting
components on the board near the mounting holes. They may have played a very minor
role in vibration/stress dampening.

~~~~~~
Bait for spammers:
root@localhost
postmaster@localhost
admin@localhost
abuse@localhost
postmaster@[127.0.0.1]
uce.DeleteThis@ftc.gov
~~~~~~
Remove "spamless" to email me.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

If you computer wont boot and you are sure that the other components
are working properly, then I don't see any problem giving the fibre
washers a try, I had a P4S8X-X motherboard that would not boot because
it could not find the IDE drives, I took it back to where I purchased
it but they said that the errors I was getting did not indicate that
the board was at fault and told me to set the motherboard up out side
the case, so I did that and it worked, so I put the computer back
together and it would not work again so I put fibre washers under the
screw heads and all was well.
Cheers

On Sun, 16 May 2004 23:57:33 GMT, Matt <matt DeleteThis @themattfella.zzzz.com>
wrote:

 >RS wrote:
  >> I am repairing a computer that has a AOpen Slot 1 motherboard that won't
  >> boot. (The CPU tests OK on another system, as does the RAM)
  >>
  >> I have purchased a used ASUS Slot 1 motherboard off of eBay. I am now in the
  >> process of swapping the motherboards and I see that the old motherboard has
  >> pieces of black electrical tape on the bottom where the mounting screws poke
  >> through. Is this necessary? I know that bags of hardware that comes with
  >> computer cases used to (I recall) include little brown "paper" washers.
  >>
  >> Thanks for any knowledgeable opinions / clarification !
  >>
  >> -RS-
  >>
  >>
 >
 >Why would mobo makers put metal circles around the mobo screw holes if
 >they didn't want the mobo to be grounded to the chassis?



eTrust EZ Antivirus Protection
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Macro data file May 11 2004 (VMD Ver 1.6)<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws? 

In article <NdTpc.5098$PQ3.426@news01.roc.ny>,
matt.RemoveThis@themattfella.zzzz.com says...

 > Why would mobo makers put metal circles around the mobo screw holes if
 > they didn't want the mobo to be grounded to the chassis?
 >
THey're not connected to anything therefore they're grounding nothing.

They're there solely to prevent you tightening it so much that you chew
the screwhead into the PCB or is that too simple an explanation?


--
Conor

If you're not on somebody's shit list, you're not doing anything
worthwhile.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: insulators needed under mobo's mounting screws?