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bulging top capacitors

A

Al

Jan 1, 1970
0
In trying to figure out why this atx pc won't start, I carefully look ed
at the motherboard. Some of the blue 'can' capacitors are straight across
the top, with the X shape. But others are bulged up. Some have a smudge
of some yellow material on the bulged tops, and one has a smudge of
black. Is this normal, or a sign of failure? Thanks.
 
Time for a new motherboard. There is a known problem with poor quality
capacitors from about 2 years ago on many brands of motherboards. Pull
the CPU now before it gets fried and buy a new mother board.
 
J

James Sweet

Jan 1, 1970
0
Al said:
In trying to figure out why this atx pc won't start, I carefully look ed
at the motherboard. Some of the blue 'can' capacitors are straight across
the top, with the X shape. But others are bulged up. Some have a smudge
of some yellow material on the bulged tops, and one has a smudge of
black. Is this normal, or a sign of failure? Thanks.

You've got a board made during the bad electrolyte fiasco, replace all the
electrolytics on the board, the bulging ones are completely shot, the rest
of them WILL fail shortly. Be sure to clean up the electrolyte that leaked
out, it's corrosive.
 
J

James Sweet

Jan 1, 1970
0
Time for a new motherboard. There is a known problem with poor quality
capacitors from about 2 years ago on many brands of motherboards. Pull
the CPU now before it gets fried and buy a new mother board.

Why not repair it? I've fixed a whole pile of motherboards with this
problem, never cost me more than about 15 bucks. THey can be tricky to
desolder though, I had to use a 140W Weller on the ones with a large ground
or vcc plane.
 
C

CJT

Jan 1, 1970
0
Al said:
In trying to figure out why this atx pc won't start, I carefully look ed
at the motherboard. Some of the blue 'can' capacitors are straight across
the top, with the X shape. But others are bulged up. Some have a smudge
of some yellow material on the bulged tops, and one has a smudge of
black. Is this normal, or a sign of failure? Thanks.

See:
http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html

I've repaired some such boards, and had one repaired by the manufacturer
at reasonable cost; whether doing so is worthwhile in your particular
case depends on factors (like cost and the hassle of switching machines)
that only you can decide.
 
R

Ross Herbert

Jan 1, 1970
0
In trying to figure out why this atx pc won't start, I carefully look ed
at the motherboard. Some of the blue 'can' capacitors are straight across
the top, with the X shape. But others are bulged up. Some have a smudge
of some yellow material on the bulged tops, and one has a smudge of
black. Is this normal, or a sign of failure? Thanks.

This is almost certainly the reason your power supply won't start. I
had this symptom on my MB and the PC would start up and then shut
down. It was intermittent at first and then proceeded to get worse.
replacing the bulging caps on the MB fixed the problem.
 
H

Harvey

Jan 1, 1970
0
James Sweet said:
Why not repair it? I've fixed a whole pile of motherboards with this
problem, never cost me more than about 15 bucks. THey can be tricky to
desolder though, I had to use a 140W Weller on the ones with a large
ground
or vcc plane.
Probably because you can buy a new motherboard cheaper than a set of new
capacitors for the older one.

And then there's the added issue of the faulty capacitors over-stressing the
regulators making them go thermally intermittent too, resulting in hours of
wasted time spent changing the capacitors only to find the mobo is no better
or even worse than it was before you started.

More info about bad mobo caps here http://badcaps.net/
 
Why not fix it? The replacement cost of a motherboard that will take a
cpu and memory from a couple of years ago is what, $45 for a good one
and it will be upgradeable to the newer and faster cpu come upgrade
time.

Then there is the opportunity cost of the time involved. If it takes
one hour to replace all the capacitors on the board, and the board does
wind up being good, how much was that one hour worth?
 
C

CJT

Jan 1, 1970
0
Harvey said:
Why not repair it? I've fixed a whole pile of motherboards with this
problem, never cost me more than about 15 bucks. THey can be tricky to
desolder though, I had to use a 140W Weller on the ones with a large
ground
or vcc plane.

Probably because you can buy a new motherboard cheaper than a set of new
capacitors for the older one.

And then there's the added issue of the faulty capacitors over-stressing the
regulators making them go thermally intermittent too, resulting in hours of
wasted time spent changing the capacitors only to find the mobo is no better
or even worse than it was before you started.

More info about bad mobo caps here http://badcaps.net/
[/QUOTE]
The flip side is that the price of the motherboard can be irrelevant
compared to the cost of new memory (since current motherboards often
use a different sort) and the time to reinstall software and get
everything working as before. And capacitors are pretty cheap; you
ought to be able to replace them all for under 30 bucks +/-.

It's not an easy call, but I've done a couple of replacements, and
they've worked well for me.
 
C

CJT

Jan 1, 1970
0
Why not fix it? The replacement cost of a motherboard that will take a
cpu and memory from a couple of years ago is what, $45 for a good one
and it will be upgradeable to the newer and faster cpu come upgrade
time.

Then there is the opportunity cost of the time involved. If it takes
one hour to replace all the capacitors on the board, and the board does
wind up being good, how much was that one hour worth?
In my experience, finding and installing a suitable replacement
motherboard will take about as long or longer. That it's "upgradeable
to the newer and faster cpu" probably means it uses a different chipset,
which means the OS may need reinstallation, too.
 
A

Art

Jan 1, 1970
0
IMHO, after the period of time it has taken for these caps to fail, and
probably contribute to other damage, would it not be apparent that one
should consider upgrading to a faster CPU, more memory, and new motherboard
that has the USB2 feature,etc built in. I have done many computers this way
for less than $200 USD and have a fine, faster, more reliable piece of
equipment afterwards. <
 
C

CJT

Jan 1, 1970
0
Art said:
IMHO, after the period of time it has taken for these caps to fail, and
probably contribute to other damage, would it not be apparent that one
should consider upgrading to a faster CPU, more memory, and new motherboard
that has the USB2 feature,etc built in. I have done many computers this way
for less than $200 USD and have a fine, faster, more reliable piece of
equipment afterwards. <

Sure -- been there, done that. But I've also been in the situation
where I've done what seemed like a simple upgrade and found that key
pieces of software could no longer be made to run due to differences
in the BIOS, etc.

Each case must be evaluated on its own merits.
 
J

James Sweet

Jan 1, 1970
0
Harvey said:
Probably because you can buy a new motherboard cheaper than a set of new
capacitors for the older one.

Where can you buy a new motherboard for less than $15?

And then there's the added issue of the faulty capacitors over-stressing the
regulators making them go thermally intermittent too, resulting in hours of
wasted time spent changing the capacitors only to find the mobo is no better
or even worse than it was before you started.

I've *never* run into a board that was intermittant after replacing the
caps, I suppose it could happen but it's rare. I say either repair the board
and keep it out of the landfill, or get a new board, CPU, RAM, etc to
upgrade to a newer generation.
 
J

James Sweet

Jan 1, 1970
0
Art said:
IMHO, after the period of time it has taken for these caps to fail, and
probably contribute to other damage, would it not be apparent that one
should consider upgrading to a faster CPU, more memory, and new motherboard
that has the USB2 feature,etc built in. I have done many computers this way
for less than $200 USD and have a fine, faster, more reliable piece of
equipment afterwards. <


It's certainly an option if you need a faster machine, but in a lot of cases
$15 to get the computer back online vs $200 plus a bunch of time
reinstalling the OS and all the applications (or if you get really lucky, a
few tricks to reinstall the drivers), replacing the caps starts to look
appealing.
 
J

JURB6006

Jan 1, 1970
0
The other thing to consider is if it's running XP it <u>will not</u> migrate to
a new mobo. You must reinstall. Any apps that have significant registry entries
also will need to be reinstalled.

If you're running 98 and change the mobo you need to start in safe mode and
remove all references to the old mobo resources. If you don't you might get
nagged by a BSOD once in a while. XP won't even get into safe mode with such a
drastic hardware change. While the hardware change bothers 98, if you can
manage not to reinstall it your apps will run right. The exception might be
certain games if you wind up with a different vidcard.

Actually anyone who's still running 98 is doing so for a very good reason.

JURB
 
It's no easy task to replace all the caps on a multi-layer board
with plated through holes. You are likely to end up with a dead board.
Try fault tracing on that one.
 
F

Franc Zabkar

Jan 1, 1970
0
Why not fix it? The replacement cost of a motherboard that will take a
cpu and memory from a couple of years ago is what, $45 for a good one
and it will be upgradeable to the newer and faster cpu come upgrade
time.

Then there is the opportunity cost of the time involved. If it takes
one hour to replace all the capacitors on the board, and the board does
wind up being good, how much was that one hour worth?

Nobody has factored in the cost of installing the software for the new
motherboard, not to mention possible additional compatibility issues.
For example, those motherboards with onboard sound, video, modem, and
LAN may need some work before all the drivers are functional. IME,
mucking about with S/W is much more problematic and time consuming
than changing a few caps.


- Franc Zabkar
 
Harvey said:
Probably because you can buy a new motherboard cheaper than a set of new
capacitors for the older one.

That's nonsense. A handfull capacitors will cost between 10 and 25
dollars, a motherboard will cost between 30 and 150 dollars.
And then there's the added issue of the faulty capacitors over-stressing the
regulators making them go thermally intermittent too, resulting in hours of
wasted time spent changing the capacitors only to find the mobo is no better
or even worse than it was before you started.

It happens, but reparing a motherboard does not take 'hours'. You put in
the electrolytics, if it does not work, take them out and throw the
board in the parts bin. Have you ever noticed the name of this
newsgroup?
 
It's no easy task to replace all the caps on a multi-layer board
with plated through holes. You are likely to end up with a dead board.
Try fault tracing on that one.

Replacing is easy. Fault finding not. Replace them using a soldering
iron of _sufficient_ power, though. If after replacing it still doesn't
work? Bad luck, consider a new board.
 
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