help a masochist diagnose his burnt motherboard

S

Sam

Guest
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board as i gave away 64mb of its ram
(it had 96Mb) to a friend and the ram is working fine on his machine
so it appears damage was limited to the lightnings path of damage to
earth.

before i toss the board i was willing to invest some time checking the
components for any shorts/open circuit damage around the PCI slots
with a multimeter.

The problem is that surface mounted components look all the same but
have different markings on the board. My question is what are the
labels R, C and CB on the board?

Any tips on what else to look for would be highly appreciated.

Thanks,
Sam


http://www.soyo.com.tw/images/products/800x600/5eas5.jpg
 
Sam wrote:
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board as i gave away 64mb of its ram
(it had 96Mb) to a friend and the ram is working fine on his machine
so it appears damage was limited to the lightnings path of damage to
earth.

before i toss the board i was willing to invest some time checking the
components for any shorts/open circuit damage around the PCI slots
with a multimeter.

The problem is that surface mounted components look all the same but
have different markings on the board. My question is what are the
labels R, C and CB on the board?

Any tips on what else to look for would be highly appreciated.

Thanks,
Sam


http://www.soyo.com.tw/images/products/800x600/5eas5.jpg
Click to expand...
Have you checked the power supply?
rw
 
this PSU fan turns and disks power up when connected. i tried a
different PSU from a good PC but board still didnt boot.

Sam

Rein Wiehler <rw@netscape.net> wrote in message news:<O3Kfb.101108$3r1.15394@news02.bloor.is.net.cable.rogers.com>...
Sam wrote:
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board as i gave away 64mb of its ram
(it had 96Mb) to a friend and the ram is working fine on his machine
so it appears damage was limited to the lightnings path of damage to
earth.

before i toss the board i was willing to invest some time checking the
components for any shorts/open circuit damage around the PCI slots
with a multimeter.

The problem is that surface mounted components look all the same but
have different markings on the board. My question is what are the
labels R, C and CB on the board?

Any tips on what else to look for would be highly appreciated.

Thanks,
Sam


http://www.soyo.com.tw/images/products/800x600/5eas5.jpg

Have you checked the power supply?
rw
Click to expand...
 
checked the surface mounted resistors and caps around the PCI slots
and they look ok.the resistors have resistence which matches the
number printed, and none of the caps are shorted. then i started
checking the big electrolytic caps.

some have a resistance of 26-40 ohms, which seems a bit weird as i
thought they should have infinite resistance after initial current
flow.

as they seem shorted and radio shack wont open till monday, if i yank
the suspect ones out of the board can i expect to see an improvement?
in other words, on a motherboard circuit is no cap better than a
shorted cap?

thanks,
Sam

Rein Wiehler <rw@netscape.net> wrote in message news:<O3Kfb.101108$3r1.15394@news02.bloor.is.net.cable.rogers.com>...
Sam wrote:
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board as i gave away 64mb of its ram
(it had 96Mb) to a friend and the ram is working fine on his machine
so it appears damage was limited to the lightnings path of damage to
earth.

before i toss the board i was willing to invest some time checking the
components for any shorts/open circuit damage around the PCI slots
with a multimeter.

The problem is that surface mounted components look all the same but
have different markings on the board. My question is what are the
labels R, C and CB on the board?

Any tips on what else to look for would be highly appreciated.

Thanks,
Sam


http://www.soyo.com.tw/images/products/800x600/5eas5.jpg

Have you checked the power supply?
rw
Click to expand...
 
To be brutally honest the board you have there is an old socket seven and
simply isn't worth spending a moment of your time on. you could get a
replacement for a few dollars or schillings or whatever. In my experience
lightning strikes are invariably fatal as high voltage pulses can do damage
deep inside a chip before the fuses open (if the fuses open at all as these
need high currents to work) . The last system that came my way after
suspected lightning damage had faults everywhere. The graphics card didn't
work, the hard drive didn't work (even though it spun up and sounded OK)
even the CD drive, and of course the mainboard and modem were both scrap,
although the processor an (Athlon 1.2G) and the SDRAM both worked OK on the
new board. Even if everything is physically OK It's possible that the bios
program has been damaged and you would need another identicle board to check
it out. take my advice and throw the board away and buy a whip.

Pete



"Sam" <ymailus@yahoo.com> wrote in message
news:a5df5561.0310041535.10c8a65@posting.google.com...
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board as i gave away 64mb of its ram
(it had 96Mb) to a friend and the ram is working fine on his machine
so it appears damage was limited to the lightnings path of damage to
earth.

before i toss the board i was willing to invest some time checking the
components for any shorts/open circuit damage around the PCI slots
with a multimeter.

The problem is that surface mounted components look all the same but
have different markings on the board. My question is what are the
labels R, C and CB on the board?

Any tips on what else to look for would be highly appreciated.

Thanks,
Sam


http://www.soyo.com.tw/images/products/800x600/5eas5.jpg
Click to expand...
 
Path: nntp.upenn.edu!info1.fnal.gov!newsfeed.stanford.edu!postnews1.google.com!not-for-mail
From: ymailus@yahoo.com (Sam)
Newsgroups: sci.electronics.repair
Subject: Re: help a masochist diagnose his burnt motherboard
Date: 4 Oct 2003 23:21:40 -0700
Organization: http://groups.google.com
Lines: 36
Message-ID: <a5df5561.0310042221.51584e58@posting.google.com>
References: <a5df5561.0310041535.10c8a65@posting.google.com> <O3Kfb.101108$3r1.15394@news02.bloor.is.net.cable.rogers.com>
NNTP-Posting-Host: 217.30.96.166
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Trace: posting.google.com 1065334900 21744 127.0.0.1 (5 Oct 2003 06:21:40 GMT)
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NNTP-Posting-Date: Sun, 5 Oct 2003 06:21:40 +0000 (UTC)
Xref: nntp.upenn.edu sci.electronics.repair:350613

this PSU fan turns and disks power up when connected. i tried a
different PSU from a good PC but board still didnt boot.
Click to expand...
I assume you have some good RAM installed.

Also, did you try resetting the CMOS?

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
ymailus@yahoo.com (Sam) writes:

checked the surface mounted resistors and caps around the PCI slots
and they look ok.the resistors have resistence which matches the
number printed, and none of the caps are shorted. then i started
checking the big electrolytic caps.

some have a resistance of 26-40 ohms, which seems a bit weird as i
thought they should have infinite resistance after initial current
flow.

as they seem shorted and radio shack wont open till monday, if i yank
the suspect ones out of the board can i expect to see an improvement?
in other words, on a motherboard circuit is no cap better than a
shorted cap?
Click to expand...
There is a lot of stuff in parallel with the caps. You can't check them
that way.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
"Sam" <ymailus@yahoo.com> wrote in message
news:a5df5561.0310041535.10c8a65@posting.google.com...
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

Just curious, how did lightning get into the network cabling? Did it run
Click to expand...
outside?
 
"Pete Culf" <hackamat@hotmail.com> wrote in message news:<blonvr$rh4$1@newsg1.svr.pol.co.uk>...
To be brutally honest the board you have there is an old socket seven and
simply isn't worth spending a moment of your time on. you could get a
replacement for a few dollars or schillings or whatever. In my experience
lightning strikes are invariably fatal as high voltage pulses can do damage
deep inside a chip before the fuses open (if the fuses open at all as these
need high currents to work) . The last system that came my way after
suspected lightning damage had faults everywhere. The graphics card didn't
work, the hard drive didn't work (even though it spun up and sounded OK)
even the CD drive, and of course the mainboard and modem were both scrap,
although the processor an (Athlon 1.2G) and the SDRAM both worked OK on the
new board. Even if everything is physically OK It's possible that the bios
program has been damaged and you would need another identicle board to check
it out. take my advice and throw the board away and buy a whip.
Click to expand...
LOL!

I've got a working S7 mini AT/ATX board (both PSU connectors) goes up
to 100*4.5
Will throw in (hehe) a cheap CPU for you to test .

Also got some RAM sticks though i cannot guarantee that they work 100%
(although it boots fine in MS-DOS) .

Email me if interested .

-A

Beware, this thing has jumpers not BIOS config . Set them right :)

Pete



"Sam" <ymailus@yahoo.com> wrote in message
news:a5df5561.0310041535.10c8a65@posting.google.com...
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board as i gave away 64mb of its ram
(it had 96Mb) to a friend and the ram is working fine on his machine
so it appears damage was limited to the lightnings path of damage to
earth.

before i toss the board i was willing to invest some time checking the
components for any shorts/open circuit damage around the PCI slots
with a multimeter.

The problem is that surface mounted components look all the same but
have different markings on the board. My question is what are the
labels R, C and CB on the board?

Any tips on what else to look for would be highly appreciated.

Thanks,
Sam


http://www.soyo.com.tw/images/products/800x600/5eas5.jpg
Click to expand...
 
In article <a5df5561.0310041535.10c8a65@posting.google.com>,
ymailus@yahoo.com says...
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board
Click to expand...
Sam,

Please take Pete's advice on this. Lightening strikes are
virtually always fatal to electronics, and given your
follow-up posts, you simply don't have the knowledge to
repair this piece, no matter how many questions you ask.
Save yourself the grief.

--
Mark

The truth as I perceive it to be.
Your perception may be different.

Triple Z is spam control.
 
"Robert Morein" <nowhere@nowhere.com> wrote in message news:<upmcnTQ4S8Z_kx2iU-KYvA@comcast.com>...
"Sam" <ymailus@yahoo.com> wrote in message
news:a5df5561.0310041535.10c8a65@posting.google.com...
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

Just curious, how did lightning get into the network cabling? Did it run
outside?
Click to expand...
thanks for all the info. i am pretty sure the lightning came in
through the NIC card as the pc it was networked with was toast too. i
had left my pc over at my friends house for some multiplayer gaming.
his had a modem, their phone line got a hit, left them without phone
for days. toasted his PC and mine. Oh well at least mine was just a
pentium 1, his was an AMD Athlon Xp.


Sam
 
Mark <ZZZmark@whiskey-creek.net> wrote in message news:<MPG.19e9e694e50b2396989784@newsgroups.bellsouth.net>...
In article <a5df5561.0310041535.10c8a65@posting.google.com>,
ymailus@yahoo.com says...
hi there,

my motherboard (photo below) got burned out through lightning via the
network card. when i power it up with CPU & ram & speaker only i get
no beeps, nothing.

i still have some hope for this board

Sam,

Please take Pete's advice on this. Lightening strikes are
virtually always fatal to electronics, and given your
follow-up posts, you simply don't have the knowledge to
repair this piece, no matter how many questions you ask.
Save yourself the grief.
Click to expand...
Yup- lightning can damage even unconnected parts ! . Seen that before
(calculator in shed locked up after a storm we had, worked fine after
it was reset) .

I heard of TV remotes being fried while sitting on a desk before now
 
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