Archived from groups: alt.comp.hardware.pc-homebuilt (
More info?)
Just a note to say that I finally got around to preceeding somewhat with the
troublesome motherboard situation. I put in a CPU that was covered by the
jumper settings specifically mentioned in the manual ... and lo and behold,
on power up it beeped, checked memory, recognized the CDROM and IDE-Zip
drive ...and looked around for a HDD ... which is not yet installed.
I looked in the BIOS and under Power Management it was indeed set to boot up
automatically after power interuption. After changing that, the power SW on
the front of the case operated normally.
That is as far as I have got so far. I did phone Asus's International
support, got through to someone who said a tech would call back. This has
not happened yet. I want to ask why there is a jumper setting in the manual
for "P2/Celeron 400" with a bus speed of 100MHz. Typo? My Celeron 400 does
not work at that setting ... not surprizingly ...
Thanks !
-RS-
"do_not_spam_me" <do_not_spam_me@my-deja.com> wrote in message
news:101710fa.0405162209.7d5ecde4@posting.google.com...
> "RS" <jf_reneX@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.