Even Intel used bad capacitors

[Leaking Caps]

The motherboard is an Intel D865PERL purchased in October 2004. Two of the
electrolytic capacitors are bulging and leaking:

http://i7.tinypic.com/8g6ywx1.jpg
http://i15.tinypic.com/7x17g5t.jpg

I can't determine their value and the board is out of warranty anyway. I
keep reading about solid state capacitors. Are those the same as a "solid
capacitor"? Instead of a tall can wrapped in plastic, the solid capacitor
is short and metal, not wrapped in plastic, and doesn't have vent holes.

 

[Lostgallifreyan]

http://i7.tinypic.com/8g6ywx1.jpg
http://i15.tinypic.com/7x17g5t.jpg

I can't determine their value

It's written on the other side. Take a few pictures, the camera flash and
magnification will get you a reading, you just have to find an angle good
enough to see it.

It's probably 10V 1000 µF. Panasonic make some good replacements.
RS Components order code 526-1115, for example. Check the lead spacing,
they're likely an exact match but maybe not.

 

[Eeyore]

The motherboard is an Intel D865PERL purchased in October 2004. Two of the
electrolytic capacitors are bulging and leaking:

http://i7.tinypic.com/8g6ywx1.jpg
http://i15.tinypic.com/7x17g5t.jpg

I can't determine their value

You're looking at the wrong side !

That's pretty mild bulging and I see no leaking.

Graham

 

[Eeyore]

It's written on the other side. Take a few pictures, the camera flash and
magnification will get you a reading, you just have to find an angle good
enough to see it.

It's probably 10V 1000 µF. Panasonic make some good replacements.
RS Components order code 526-1115, for example. Check the lead spacing,
they're likely an exact match but maybe not.

Any idea why such caps are very often 10V rated and not 6.3V ?

Graham

 

[Hal Murray]

Any idea why such caps are very often 10V rated and not 6.3V ?

Probably to get the current rating that they need. They probably
need a bigger package to get rid of the heat and the extra
voltage comes along with that.

 

[Lostgallifreyan]

Any idea why such caps are very often 10V rated and not 6.3V ?

Not really sure, but I guess it's a general principle of overrating being
likely to improve life and performace if it's not significantly more
expensive. Could argue for lots of stuff like higher ripple current, lower
ESR, better heat dissipation if the can is bigger, better surge resistance,
but in the end I doubt they calculate all that, they probably just test with
one cap, then uprate to the next voltage for production on the grounds that
it's cheaper if many are the same, and it probably makes less returns.

In short, crude uprating and using lots of equal parts costs less than trying
to design their performance to precise limits. Same as it's always easier to
fligh high and straight than to hug the ground to avoid radar, even though
the initial cost of getting up there is greater.

 

[Leaking Caps]

OK, I took some more pictures and got their value. They are Nichicon
brand, 560uF 6.3volt. Both of them show signs of oozing an amber liquid
from the top.

http://i10.tinypic.com/855aihf.jpg

The board was stable if I had one piece of memory installed. If I had two
pieces installed, same brand and part#, I would get random crashes.

 

[Lostgallifreyan]

OK, I took some more pictures and got their value. They are Nichicon
brand, 560uF 6.3volt. Both of them show signs of oozing an amber liquid
from the top.

http://i10.tinypic.com/855aihf.jpg

The board was stable if I had one piece of memory installed. If I had two
pieces installed, same brand and part#, I would get random crashes.

You could uprate to those 10V 1000µF caps I mentioned. Capacitance tolerance
alone can change from nominal 560 to 20% more, it's not that critical.
Adequate supply smoothing to memory modules IS though. So check the lead
spacings. If they match, get some. Get several tens of them even, they'll
replace other caps you haven't found yet, probably. Most firms like to stick
to standard values, so you won't go far wrong buying between 20 and 100 of
RS's part 526-1115. As far as I know, they only buy from direct sources where
possible, I've not yet seen any problems with parts bought from them.
Probably same with Mouser and Digikey, etc, I doubt they'd risk buying from
loose sourcing that let in counterfeits easily, it would damage them too much
if that happened.

 

[Eeyore]

OK, I took some more pictures and got their value. They are Nichicon
brand, 560uF 6.3volt. Both of them show signs of oozing an amber liquid
from the top.

http://i10.tinypic.com/855aihf.jpg

The board was stable if I had one piece of memory installed. If I had two
pieces installed, same brand and part#, I would get random crashes.

One of those is a Nichicon part. I don't recall those being affected by the
'bad caps' issue so it's probably just simply 'worn out' from extended use.

Graham

 

[www.interfacebus.com]

The motherboard is an Intel D865PERL purchased in October 2004.  Two of the
electrolytic capacitors are bulging and leaking:

http://i7.tinypic.com/8g6ywx1.jpghttp://i15.tinypic.com/7x17g5t.jpg

I can't determine their value and the board is out of warranty anyway.  I
keep reading about solid state capacitors.  Are those the same as a "solid
capacitor"?  Instead of a tall can wrapped in plastic, the solid capacitor
is short and metal, not wrapped in plastic, and doesn't have vent holes.

Those are Aluminum Electrolytic Capacitors

http://www.interfacebus.com/Electrolytic_Capacitor_Manufacturers.html

I haven't heard of this issue for a few years now

 

[www.interfacebus.com]

Any idea why such caps are very often 10V rated and not 6.3V ?

Graham

Standard design pratice is to over rate the component value. The
common term is derating;

http://www.interfacebus.com/Component_Derating_Guide_line.html

 

[Eeyore]

Those are Aluminum Electrolytic Capacitors

http://www.interfacebus.com/Electrolytic_Capacitor_Manufacturers.html

I haven't heard of this issue for a few years now

It's pretty much fixed but rumour has it that some manufacturers are still
shipping duff stock. But that's rumour.

Graham

 

[Eeyore]

Standard design pratice is to over rate the component value. The
common term is derating;

http://www.interfacebus.com/Component_Derating_Guide_line.html

Yes I'm aware of that but advice I've had from cap makers is that it's completely
unneccesary. It affects ONLY leakage current and that's largely unimportant.

Graham

 

[www.interfacebus.com]

Yes I'm aware of that but advice I've had from cap makers is that it's completely
unneccesary. It affects ONLY leakage current and that's largely unimportant.

Graham- Hide quoted text -

- Show quoted text -

Really, there are a number of working engineers that produce designs
under a mandatory derating. I think mine is 10%. I won't walk into a
design review with a 6V cap working off a 6 volt line..

Most of the derating guidelines I provide are from Military standards,
some maybe from NASA

http://www.interfacebus.com/
http://interfacebus.blogspot.com/

 

[Eeyore]

Really, there are a number of working engineers that produce designs
under a mandatory derating. I think mine is 10%. I won't walk into a
design review with a 6V cap working off a 6 volt line..

Simply out of prudence neither would I normally but I have the following tale to tell.

I was designing an audio power amp and to meet the desired power output, the supply
rails were ~ 67V off-load. That would have ruled out 63V caps for the psu but the
manager was so concerned about cost that he spoke to the cap makers and asked for their
advice.

They repsonded that there would only be a very mild increase in leakage current and
that the caps were designed for at least a 10% 'overvoltage' anyway.

So we used 63V caps on a supply that was 67V off-load and we had ZERO reliability
problems with that. In fact it was one of the most reliable products that the company
ever made.

Most of the derating guidelines I provide are from Military standards,
some maybe from NASA

Yes but most kit isn't intended for military or aerospace use. Most deratings are
historically based AIUI and modern components really don't need it.

Graham

 

[Michael A. Terrell]

Yes but most kit isn't intended for military or aerospace use. Most deratings are
historically based AIUI and modern components really don't need it.

That's why most consumer electronics dies within two years.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Hal Murray]

Yes but most kit isn't intended for military or aerospace use. Most deratings are
historically based AIUI and modern components really don't need it.

I'd expect electrolytics to last a lot longer if they are kept cool
and/or run below rated voltage.

 

[www.interfacebus.com]

Simply out of prudence neither would I normally but I have the following tale to tell.

I was designing an audio power amp and to meet the desired power output, the supply
rails were ~ 67V off-load. That would have ruled out 63V caps for the psu but the
manager was so concerned about cost that he spoke to the cap makers and asked for their
advice.

They repsonded that there would only be a very mild increase in leakage current and
that the caps were designed for at least a 10% 'overvoltage' anyway.

So we used 63V caps on a supply that was 67V off-load and we had ZERO reliability
problems with that. In fact it was one of the most reliable products that the company
ever made.


Yes but most kit isn't intended for military or aerospace use. Most deratings are
historically based AIUI and modern components really don't need it.

Graham- Hide quoted text -

- Show quoted text -

I'm just saying that's where I got the data, not what I was designing
for.

Cable company called the othet day, wanted me to buy VOIP.

I told them their service sucks, there was no way I would purchase
anything.
But you have not Complained since 2002?

How many people just move to another product?

http://www.interfacebus.com/

 

[Eeyore]

That's why most consumer electronics dies within two years.

No it doesn't.

Graham

 

[Eeyore]

I'd expect electrolytics to last a lot longer if they are kept cool

Correct. that's VITAL

and/or run below rated voltage.

Utterly WRONG. This is pure myth.

Graham