Electro Cap Warning

How did you test the ESR?

Dan

** Silly question !!!

Bob " Mr ESR Meter " Parker will be along to put you straight, any mo.

...... Phil

My Gigabyte motherboard's the same age as yours. Late last year it started crashing on startup, and yes, some of the 'GSC' electros had bulging/split/leaking tops. The main culprits around the CPU voltage regulator were a pair of 'GSC' 3300uF 6.3V ones, with ESR readings of 0.7 and 0.8 ohms. Replaced them with WES's 105C low ESR 10V ones, along with four swollen 1500uF

16V, and it's been fine ever since. I understand that GSC caps were one of the brands involved in the defective electrolyte fiasco.

Bob

Phil used his DSE K-7204 ESR meter to measure them. I used mine to check my motherboard caps too.

Bob

Oh

I was wondering what all the fuss about 'long life solid capacitors' was all about. I thought "What a load of crap as if your motherboard capacitors ever go faulty"

I guess I was wrong :S

____________________________________________________ "I like to be organised. A place for everything. And everything all over the place."

A few years ago, millions of electrolytic caps were made in Asia with defective electrolyte. Many of them went into motherboards which started failing after a period ranging from a few months to a few years. It's such a major problem that there are discussion forums about it on the subject, e.g.

have a read of this

** Hi to all my loyal fans ....

Had to perform "emergency surgery" on my PC on Friday morning - PC is about 4 years old & uses a " Gigabyte" mother board with Athlon 1.8G CPU. Runs XP.

It simply froze & refused to complete boot up and presented a totally black screen when switched off & re-tried.

Same scenario was repeated exactly, after 20 minutes of being off.

Suspecting a " heat "issue - I got out the vacuum and gave the insides a good clean, its was pretty bad around the CPU heatsink & fan.

Tried it again - same scenario.

Damn !!

Then, I noticed some VERY hot mosfets ( finger burning temp) in the CPU regulators and some rather bulged and wonky looking electros next to them - one 1000uF, 6.3 volt Sanyo and two 1200uF, 6.3 volt "GSC ".

Extracted some similar spec electros from another (unused) motherboard and replaced the dud ones in my PC - the new caps tested extremely low ESR, about 30 - 40 milliohms !!

Voila - the PC works fine again and the previously hot mosfets now run only luke warm. Feeling very pleased :-)

Checked out the three faulty electros and found they were all open circuit, the best one had an ESR of about 10 kohms !!!

How the heck could it function AT ALL with O/C caps like that ??

Moral:

Check out all those hard working regulator electros from time to time and replace the lot at the first sign of cap bulging or hot mosfets.

....... Phil

this

You are right about that.

I also have a Soltek and a Gigabyte board here in my junk box from that era (about 2001-3). Both had faulty (swelled and starting to leak) caps on the board that sound exactly like what you have discovered.

At the time they failed (2005?), I looked into replacing the caps, but considering the high price for these special low ESR electros from Farnell at the time, and the large numbers of them used on these 2 boards, not to mention that the motherboards weren't working, and might have other faults too, I replaced the motherboards with new ones. (This also gave other benefits like no 32/128gig hard drive size limit, etc).

Last year, I saw similar problems on a friend's Aopen board. Replacing the caps with ones from another dead motherboard (that didnt have leaky caps) fixed it perfectly.

As for the thing still working, I am surprised what motherboards seem able to cop, and keep on working. Last year one of my workmates f****it relatives brought to him a home assembled PC claiming the "power button wont work, have to switch off at the mains all the time". To his amazement, the motherboard was screwed directly to the metal chassis, with no spacers. Im absolutely astounded that the thing even powered up and wonder why it didnt simply act as a huge short circuit !

"kreed"

** Yep - there were lots of other " GSC " electros on the same motherboard.

All of them looked just fine & tested perfect on Bob's ** fabulous** ESR meter.

All of them had no heat sources nearby....

Hardly a coincidence after circa 15,000 hrs operation

** Mug's luck.

See it all the bloody time !!!!!!!!!!!!!!!!!!!!

Makes me wanna puke ......

....... Phil ;-)

reply on top d*****ad so we can read it

this

circuit,

You are right about that.

I also have a Soltek and a Gigabyte board here in my junk box from that era (about 2001-3). Both had faulty (swelled and starting to leak) caps on the board that sound exactly like what you have discovered.

At the time they failed (2005?), I looked into replacing the caps, but considering the high price for these special low ESR electros from Farnell at the time, and the large numbers of them used on these 2 boards, not to mention that the motherboards weren't working, and might have other faults too, I replaced the motherboards with new ones. (This also gave other benefits like no 32/128gig hard drive size limit, etc).

Last year, I saw similar problems on a friend's Aopen board. Replacing the caps with ones from another dead motherboard (that didnt have leaky caps) fixed it perfectly.

As for the thing still working, I am surprised what motherboards seem able to cop, and keep on working. Last year one of my workmates f****it relatives brought to him a home assembled PC claiming the "power button wont work, have to switch off at the mains all the time". To his amazement, the motherboard was screwed directly to the metal chassis, with no spacers. Im absolutely astounded that the thing even powered up and wonder why it didnt simply act as a huge short circuit !

d*****ad top post to save us time

"kreed"

** Yep - there were lots of other " GSC " electros on the same motherboard.

All of them looked just fine & tested perfect on Bob's ** fabulous** ESR meter.

All of them had no heat sources nearby....

Hardly a coincidence after circa 15,000 hrs operation

** Mug's luck.

See it all the bloody time !!!!!!!!!!!!!!!!!!!!

Makes me wanna puke ......

....... Phil ;-)

** Hi to all my loyal fans ....

Had to perform "emergency surgery" on my PC on Friday morning - PC is about 4 years old & uses a " Gigabyte" mother board with Athlon 1.8G CPU. Runs XP.

It simply froze & refused to complete boot up and presented a totally black screen when switched off & re-tried.

Same scenario was repeated exactly, after 20 minutes of being off.

Suspecting a " heat "issue - I got out the vacuum and gave the insides a good clean, its was pretty bad around the CPU heatsink & fan.

Tried it again - same scenario.

Damn !!

Then, I noticed some VERY hot mosfets ( finger burning temp) in the CPU regulators and some rather bulged and wonky looking electros next to them - one 1000uF, 6.3 volt Sanyo and two 1200uF, 6.3 volt "GSC ".

Extracted some similar spec electros from another (unused) motherboard and replaced the dud ones in my PC - the new caps tested extremely low ESR, about 30 - 40 milliohms !!

Voila - the PC works fine again and the previously hot mosfets now run only luke warm. Feeling very pleased :-)

Checked out the three faulty electros and found they were all open circuit, the best one had an ESR of about 10 kohms !!!

How the heck could it function AT ALL with O/C caps like that ??

Moral:

Check out all those hard working regulator electros from time to time and replace the lot at the first sign of cap bulging or hot mosfets.

....... Phil

On 9 Apr 2007 04:50:03 -0700, "kreed" put finger to keyboard and composed:

I presume there were no plug-in cards? What about the rear keyboard, USB, mouse, graphics sockets? How did they fit?

- Franc Zabkar

--
Please remove one 'i' from my address when replying by email.

I didn't see it, it was brought to my workmate's house, by the relative and he told us about it the following day. I assume that they didnt use the clip-in rectangular surround in the back of the case that usually comes with a new motherboard, or maybe left that end of the board up in the air (that would explain the thing not shorting I guess) I didn't think to ask at the time.

Reply in context d*****ad so it makes sense