Coil beyond repair?
 

I have a motherboard with a slightly "roasted" coil that I'm interested in
knowing if it is possible to replace and make the board work again.

Have a look at these two images:

http://www.meradan.se/albums/album45/IMG_2210.sized.jpg (component side)
http://www.meradan.se/albums/album45/IMG_2211.sized.jpg (solder side)

I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could it
be any more components? If the latter, how can I find out if that's the case?


--
Sincerely, | http://bos.hack.org/cv/
Rikard Bosnjakovic | Code chef - will cook for food
------------------------------------------------------------------------

Coil beyond repair?
 

Den Thu, 27 Oct 2005 08:16:04 +0000. skrev Rikard Bosnjakovic:


I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could it
be any more components? If the latter, how can I find out if that's the case?

Before you change the coil you shoud concider to replace all the
electrotytics, they seems to be bulky and leaking. Dead electrolytics are
a likely reason for the high current drawn. The coil are only for noise
reduction purposes, You can replace it with a jumper or any other coil
with the same wire gauge.

--
Best regards OZ1GNN

Christian Treldal

Coil beyond repair?
 

On Thu, 27 Oct 2005 08:16:04 GMT, Rikard Bosnjakovic
wrote:

I have a motherboard with a slightly "roasted" coil that I'm interested in
knowing if it is possible to replace and make the board work again.

Have a look at these two images:

http://www.meradan.se/albums/album45/IMG_2210.sized.jpg (component side)
http://www.meradan.se/albums/album45/IMG_2211.sized.jpg (solder side)

I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could it
be any more components? If the latter, how can I find out if that's the case?

There has got to be more bad than just the coil. Like the other
responder suggests check the electrolytic's for shorts or replace
them. Looks like you may have some collateral damage to the nearby
connector.

That gray fuzzy lint-like stuff splattered around the heatsink, looks
like the remains of an electrolytic cap that tried for a sub orbital
launch. Look for a missing component labeled C something, and the
aluminum can and rubber plug. The leads may or may not be still on
the board somewhere.

For a coil of that gauge wire to burn you pulled some very heavy
current. Likely as not, through a very large board trace to a
regulator or filter cap which is the initial problem.

Motherboards are multi layer boards with perhaps as many as 5 layers
of traces between the two surfaces you can see. There may be damage
that will not be evident that will be near impossible to repair. I'd
look for the obvious stuff and replace it if it's easy to do, but I
wouldn't make a career out of trying to fix that board . . .

Look for a shorted power diode, capacitor, regulator IC. That choke
will need to be replaced also - it looks like it may be cracked and
that would alter (lower) the inductance dramatically. It is probably
part of a boost or buck voltage converter. It is also close to big
IC's (processor?) with heatsinks - those may also be the root cause.
--

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Coil beyond repair?
 

On Thu, 27 Oct 2005 08:16:04 GMT, Rikard Bosnjakovic wrote:


I have a motherboard with a slightly "roasted" coil that I'm interested in
knowing if it is possible to replace and make the board work again.

Have a look at these two images:

http://www.meradan.se/albums/album45/IMG_2210.sized.jpg (component side)

Forget the coil, look at those caps! They're blown.

There where a gadzillion motherboards made around '99-'00 that had defective
caps. You got one of them. If your time is worth more than a buck an hour
then you should just replace the board. Boards from that era can be had,
and without the defective caps, for under twenty dollars.

Coil beyond repair?
 

Looking at that 1st Jpg it looks like all those filter caps needs changing
they are swollen.

kip
"Rikard Bosnjakovic" wrote in message
...
I have a motherboard with a slightly "roasted" coil that I'm interested in
knowing if it is possible to replace and make the board work again.

Have a look at these two images:

http://www.meradan.se/albums/album45/IMG_2210.sized.jpg (component side)
http://www.meradan.se/albums/album45/IMG_2211.sized.jpg (solder side)

I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could it
be any more components? If the latter, how can I find out if that's the
case?


--
Sincerely, | http://bos.hack.org/cv/
Rikard Bosnjakovic | Code chef - will cook for food
------------------------------------------------------------------------

Coil beyond repair?
 

"kip" writes:

Looking at that 1st Jpg it looks like all those filter caps needs changing
they are swollen.

Replace the mainboard. Not worth the time and agony.

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

kip
"Rikard Bosnjakovic" wrote in message
...
I have a motherboard with a slightly "roasted" coil that I'm interested in
knowing if it is possible to replace and make the board work again.

Have a look at these two images:

http://www.meradan.se/albums/album45/IMG_2210.sized.jpg (component side)
http://www.meradan.se/albums/album45/IMG_2211.sized.jpg (solder side)

I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could it
be any more components? If the latter, how can I find out if that's the
case?

Coil beyond repair?
 

"Sam Goldwasser" wrote in message
...

Replace the mainboard. Not worth the time and agony.


Absolutely agreed.

Apart from the time and effort required for a repair, would anyone in their
right mind want to chance their CPU in that motherboard? I know I wouldn't!
Apart from all the leaking, bulging caps and possible electrolyte damage to
the board, the burned coils suggests the switching regulator fets could be
shorted. The CPU would be fried pretty quickly if that's the case.

Dave

Coil beyond repair?
 

Rikard Bosnjakovic wrote:
I have a motherboard with a slightly "roasted" coil that I'm interested
in knowing if it is possible to replace and make the board work again.

Have a look at these two images:

http://www.meradan.se/albums/album45/IMG_2210.sized.jpg (component side)
http://www.meradan.se/albums/album45/IMG_2211.sized.jpg (solder side)

I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could
it be any more components? If the latter, how can I find out if that's
the case?




You can rewind it, but you'll have to replace all those bulging
capacitors first and clean up the leaky electrolyte, that was probably
the original problem. Likely you'll have at least one shorted mosfet too
which burned up the coil.

Coil beyond repair?
 

Christian Treldal wrote:
Den Thu, 27 Oct 2005 08:16:04 +0000. skrev Rikard Bosnjakovic:



I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could it
be any more components? If the latter, how can I find out if that's the case?


Before you change the coil you shoud concider to replace all the
electrotytics, they seems to be bulky and leaking. Dead electrolytics are
a likely reason for the high current drawn. The coil are only for noise
reduction purposes, You can replace it with a jumper or any other coil
with the same wire gauge.



The coil may well be quite critical if it's part of the buck regulator
used to supply power to the CPU, it's only a few turns but they often
run at 500KHz so you don't need many.

Coil beyond repair?
 

"Dave D" writes:

"Sam Goldwasser" wrote in message
...

Replace the mainboard. Not worth the time and agony.


Absolutely agreed.

Apart from the time and effort required for a repair, would anyone in their
right mind want to chance their CPU in that motherboard? I know I wouldn't!
Apart from all the leaking, bulging caps and possible electrolyte damage to
the board, the burned coils suggests the switching regulator fets could be
shorted. The CPU would be fried pretty quickly if that's the case.

May already be fried.....

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

Coil beyond repair?
 

Also note the burn in the power connector socket. Even the powersupply is
questionable now.

I just repaired one that had 6 plus caps going bad. Had not failed but caps
were domed.

Took 2 plus hours, had to use a 100 watt iron to desolder some of the caps
as there were heavy ground planes inside the board.

Not worth the work if you have to order the caps (and they are special hi
temp / low ESR) and the board is dead.

Seen many of these, fixed more than a few, some just for the challange.

Hugh
Computer Repair center owner / head tech.


"Rikard Bosnjakovic" wrote in message
...
I have a motherboard with a slightly "roasted" coil that I'm interested in
knowing if it is possible to replace and make the board work again.

Have a look at these two images:

http://www.meradan.se/albums/album45/IMG_2210.sized.jpg (component side)
http://www.meradan.se/albums/album45/IMG_2211.sized.jpg (solder side)

I know it is difficult to give a clear opinion only by looking, but what
would be your guess? Could it be only the coil that's toasted, or could it
be any more components? If the latter, how can I find out if that's the
case?


--
Sincerely, | http://bos.hack.org/cv/
Rikard Bosnjakovic | Code chef - will cook for food
------------------------------------------------------------------------