faulty capasitors

HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might be
due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR

"Juve" wrote in message
...
HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might be
due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR

No need for a meter to check the capacitors on a motherboard. When they go
bad the ends of them rupture and leak. Visually check each of them and if
they are leaking a substance (usually dark in color) then they are bad, if
not don't worry about them.

For what it's worth, the capacitors usually have a couple of little grooves
in the ends of them. They are actually there to allow the capacitor to
break open at that point and allow pressure to escape in an emergency.
During an electrical short the older one's that did not have the relief
grooves would explode like a firecracker causing much damage.

Heres what they look like 'Bad Caps in Mobos'
(http://home.earthlink.net/%7Edoniteli/index27.htm), they can also
develop a high internal resistance with age due to the electrolyte
drying out... but swelling and bulging is a common thing.

Here's another link responsible for 'bad caps' apparently due to
industrial espoinage....! 'Hushed up.'
(http://www.pcmag.com/article2/0,4149,939887,00.asp) It should be noted
this only applies to certain capacitors and not all the capacitors of
that brand and it probably may not be related to your problem
specifically.

I've changed a couple of the green GSL types but quite a while back
now, from memory I think they were Luxor or something like that.

Always use high temperature low ESR types where heat and high ripple
pulses are concerned, capacitors do go bad with age and heat though, the
gunge they sometimes leak will eat the protective lacquer on the mobo
and gobble the copper tracks in no time.

Davy

Juve wrote:
HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might be
due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR

Bulging caps indicates internal failure and a pressure buildup.
The stress relief lines break open, when enough pressure is
present. The bottom (rubber) seal, can also start to
protrude below the capacitor body, and cause the cap to
tilt on an angle.

http://www.badcaps.net/images/caps/kt7/image004.png

Brown color on the top of the caps, is from leaking electrolyte.
The brown liquid can also dry on the motherboard surface. (This
is a picture of the inside of an ATX supply, but the same problem
can happen on the motherboard.)

http://upload.wikimedia.org/wikipedi...4/PSU_Caps.jpg

Capacitance can be measured with some multimeters, if they have
a capacitance option. My $100 meter can measure capacitance, but
only for a restricted set of ranges. If the capacitor is
resistively leaky, I'm not sure whether the multimeter could
get a proper reading or not.

Paul

Juve wrote:

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might be
due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?

www.badcaps.net

As others have said, you'll usually see a bulged top on a bad
capacitor, but a multimeter or even a capacitance meter will rarely
show anything wrong with such capacitors. An ESR (equivalent series
resistance) meter is needed, but it's not useful for motherboards
because the capacitors are wired in parallel.

Juve wrote:
HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might be
due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR
Because you say "occationally harddrive is not detected at start up" I
like to ask, did you check the CMOS battery?
If that's the culprit the computer time, while the computer has been
off, might be wrong.

"Juve" skrev i meddelelsen
...
HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might be
due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR


Might also be your PSU, try changing it

--

Mvh

JBJ

Open up the case and look with a flashlight. Bad capacitors will be
discolored on top. Usually due to air moisture.


"JBJ" wrote in message
k...
"Juve" skrev i meddelelsen
...
HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might be
due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR


Might also be your PSU, try changing it

--

Mvh

JBJ

Somewhere on teh intarwebs "Maggy" typed:
Open up the case and look with a flashlight. Bad capacitors will be
discolored on top. Usually due to air moisture.

Once upon a time all advice given here was qualtiy advice....
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)

"JBJ" wrote in message
k...
"Juve" skrev i meddelelsen
...
HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might
be due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR


Might also be your PSU, try changing it

--

Mvh

JBJ

Don't be so quick to criticize Shaun. Poor quality mobo's (cheap) often
react badly to humidity.
I've seen the results and believe me, (or not) the top end of capacitors are
very prone to corrosion.
this is just one possibility to the op problem.



"~misfit~" wrote in message
...
Somewhere on teh intarwebs "Maggy" typed:
Open up the case and look with a flashlight. Bad capacitors will be
discolored on top. Usually due to air moisture.

Once upon a time all advice given here was qualtiy advice....
--
Shaun.

DISCLAIMER: If you find a posting or message from me
offensive, inappropriate, or disruptive, please ignore it.
If you don't know how to ignore a posting, complain to
me and I will be only too happy to demonstrate... ;-)

"JBJ" wrote in message
k...
"Juve" skrev i meddelelsen
...
HI,

Mobo has been on and off for the last couple of weeks. (occationally
harddrive is not detected at start up) Someone suggested this might
be due to bad capasitators. How does one gauge the "capasity" of
capasitors? Multimeter?
OR


Might also be your PSU, try changing it

--

Mvh

JBJ