laptop power fault: compaq presario C300EA

[bz]

emailaddress@insightbb.com wrote in news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f5ef@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to top edge and ~1/8
distance to right edge, with brown polarity bands, opposite polarity, bands
out.

There are almost certainly others but resolution insufficient.

I see at least 3 on the bottom view, one near the top edge center and two
near the bottom edge center, partially hidden by a wiring bundle.

Any cap over 10 uF will probably be electrolytic.




--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[Conor]

In article <3lfpp4tcbhq7pe7jv61ssnbcslfg3tvro1@4ax.com>, rebel says...

I wouldn't buy any laptop using electrolytics other than in an external
power brick.

I guess you'll never own one then ....

There speaks someone who knows fuck all about electronics. If you did,
you'd know why electrolytic caps in a laptop is generally considered "A
Bad Idea".


--
Conor

I only please one person per day. Today is not your day. Tomorrow isn't
looking good either. - Scott Adams

 

[Conor]

In article <Xns9BB7430C6B726WQAHBGMXSZHVspammote@130.39.198.139>, bz
says...

emailaddress@insightbb.com wrote in news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f5ef@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to top edge and ~1/8
distance to right edge, with brown polarity bands, opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top edge center and two
near the bottom edge center, partially hidden by a wiring bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.


--
Conor

I only please one person per day. Today is not your day. Tomorrow isn't
looking good either. - Scott Adams

 

[David]

"Conor" <conor_turton@hotmail.com> wrote in message
news:705dd7Fn2gvcU3@mid.individual.net...

In article
Xns9BB7430C6B726WQAHBGMXSZHVspammote@130.39.198.139>, bz
says...

emailaddress@insightbb.com wrote in
news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f5ef@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to
top edge and ~1/8
distance to right edge, with brown polarity bands,
opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top
edge center and two
near the bottom edge center, partially hidden by a wiring
bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.


--
Conor

Actually most laptops use tantalum polarized capacitors
which are a type of electrolytic capacitor. What they avoid
are the more common aluminum electrolytic capacitors.
Ceramics are available in low voltages at quite high
capacitance values, but I have yet to see one over 10 uF.

David

 

[Conor]

In article <Vefnl.12460$8_3.12270@flpi147.ffdc.sbc.com>, David says...

"Conor" <conor_turton@hotmail.com> wrote in message
news:705dd7Fn2gvcU3@mid.individual.net...
In article
Xns9BB7430C6B726WQAHBGMXSZHVspammote@130.39.198.139>, bz
says...

emailaddress@insightbb.com wrote in
news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f5ef@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to
top edge and ~1/8
distance to right edge, with brown polarity bands,
opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top
edge center and two
near the bottom edge center, partially hidden by a wiring
bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.


--
Conor

Actually most laptops use tantalum polarized capacitors
which are a type of electrolytic capacitor. What they avoid
are the more common aluminum electrolytic capacitors.
Ceramics are available in low voltages at quite high
capacitance values, but I have yet to see one over 10 uF.

Beat me to it. Was just going to post a link to a piccy of a tantalum.

--
Conor

I only please one person per day. Today is not your day. Tomorrow isn't
looking good either. - Scott Adams

 

On Feb 19, 10:57 am, "David" <some...@somewhere.com> wrote:

"Conor" <conor_tur...@hotmail.com> wrote in message

news:705dd7Fn2gvcU3@mid.individual.net...



In article
Xns9BB7430C6B726WQAHBGMXSZHVspamm...@130.39.198.139>, bz
says...

emailaddr...@insightbb.com wrote in
news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f...@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to
top edge and ~1/8
distance to right edge, with brown polarity bands,
opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top
edge center and two
near the bottom edge center, partially hidden by a wiring
bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.

--
Conor

Actually most laptops use tantalum polarized capacitors
which are a type of electrolytic capacitor. What they avoid
are the more common aluminum electrolytic capacitors.
Ceramics are available in low voltages at quite high
capacitance values, but I have yet to see one over 10 uF.

David

Nope. There are wet tantalum capacitors (that exist), but nobody uses
those in laptops. In laptops you find surface mount dry tantalums
among other solid types, not electrolytic at all... again, this refers
to semi-modern laptops, not something really ancient.

 

On Feb 19, 7:35 am, bz <bz+...@ch100-5.chem.lsu.edu> wrote:

emailaddr...@insightbb.com wrote in news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f...@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to top edge and ~1/8
distance to right edge, with brown polarity bands, opposite polarity, bands
out.

?? You have not indicated any electrolytic caps (but that's to be
expected since there aren't any).

There are almost certainly others but resolution insufficient.

Other caps yes, but not electrolytic. I made that picture on a
scanner, how high a resolution can you handle?
Think these are 600DPI, roughly 6000x6000 res. so I'd recommend not
trying to open them directly in a web browser.
~ 11MB Top Scan http://69.36.166.207/usr_1034/Top.jpg
~ 7MB Bottom http://69.36.166.207/usr_1034/Bottom.jpg

I see at least 3 on the bottom view, one near the top edge center and two
near the bottom edge center, partially hidden by a wiring bundle.

Caps yes, tantalum or other solid types like niobium. I suppose I
should clarify that sometimes I'll see people calling solid
capacitors, "solid electrolytic" but that is a misnomer, electrolytic
implies a liquid electrolyte. Perhaps they really meant solid
aluminum (can).

Any cap over 10 uF will probably be electrolytic.

Practically all (on that example board scan) that aren't ceramic are
over 10uF, none of which are electrolytic. Certainly years ago this
would have been near impossible at any reasonable price, but great
gains have been made in solid capacitors in the last 8 years or so,
give or take.

 

[Jerry Peters]

In sci.electronics.repair Conor <conor_turton@hotmail.com> wrote:

In article <Xns9BB7430C6B726WQAHBGMXSZHVspammote@130.39.198.139>, bz
says...

emailaddress@insightbb.com wrote in news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f5ef@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to top edge and ~1/8
distance to right edge, with brown polarity bands, opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top edge center and two
near the bottom edge center, partially hidden by a wiring bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.

Any cap over .1 uF or so will probably be an electro.

Jerry

 

[Jerry Peters]

In sci.electronics.repair emailaddress@insightbb.com wrote:

On Feb 19, 10:57 am, "David" <some...@somewhere.com> wrote:
"Conor" <conor_tur...@hotmail.com> wrote in message

news:705dd7Fn2gvcU3@mid.individual.net...



In article
Xns9BB7430C6B726WQAHBGMXSZHVspamm...@130.39.198.139>, bz
says...

emailaddr...@insightbb.com wrote in
news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f...@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to
top edge and ~1/8
distance to right edge, with brown polarity bands,
opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top
edge center and two
near the bottom edge center, partially hidden by a wiring
bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.

--
Conor

Actually most laptops use tantalum polarized capacitors
which are a type of electrolytic capacitor. What they avoid
are the more common aluminum electrolytic capacitors.
Ceramics are available in low voltages at quite high
capacitance values, but I have yet to see one over 10 uF.

David

Nope. There are wet tantalum capacitors (that exist), but nobody uses
those in laptops. In laptops you find surface mount dry tantalums
among other solid types, not electrolytic at all... again, this refers
to semi-modern laptops, not something really ancient.

A tatalum cap is a type of electrolytic. Specifically the dielectric
is formed by electro-chemical action.

Jerry

 

[Jerry Peters]

In sci.electronics.repair emailaddress@insightbb.com wrote:

On Feb 18, 6:25 pm, Jerry Peters <je...@example.invalid> wrote:
In sci.electronics.repair emailaddr...@insightbb.com wrote:
On Feb 17, 6:35 pm, "tg" <t...@nospamevereverever.net> wrote:
I have a Compaq laptop Model Presario, service tag C300EA that will not
start. It's this one:http://www.microdevices.lk/images/Laptop.jpg
the motherboard is an IBL30 LA-3324P and they retail for about Ł125.
ouch
The problem is when I plug a power supply into it and press the on/off
button the power led flashes rapidly for a few seconds and then cuts
out. I then have to wait about a minute before it will light up again.
I've tried three different power supplies, one of them coming from a
battery/voltage converter and all three power supplies produce the same
fault on the laptop so it's not the power supply. It acts the same with
or without a battery fitted. When the power supply is plugged in I did
notice the battery icon flickers all the time with no battery in.
I also connected an amp meter to the power supply and when the power
light does flicker there is virtually no current draw into the laptop.
I split the chassis to take a look and saw that the power socket wires
go straight onto the motherboard. There is no power board or
daughtercard as such..
does anyone have an idea if there's a known component that causes this
problem? or is it a case of new motherboard?
thanks for any pointers.

The symptoms suggest a short on the mainboard, the PSU aren't able to
regulate so their protection circuits are cycling them off as best
they can (at the price-point of the design).

There isn't much you can do at this point except strip the mainboard
down as much as possible.  Disconnect hard drive, optical, memory, CPU
(except if you take the heatsink off and it was heatsinking the
chipset, you must put that heatsink back on and ensure it makes good
contact with the chipset still), card reader, screen, inverter board.
See if it will then "seem" (since you have no screen, watch the power
LED(s)) to stay on.  It may not, without a processor and memory.  If
necessary put those back in and retry.  If it stays on, reconnect
screen but not the backpanel lighting inverter yet.  If it turns on
and stays on, see if there is output to the screen by shining a strong
flashlight on it.

If it works this far, an inverter failure is a common cause.  If it
didn't work at all up to this point, mainboard probably needs
replaced.  If it works up to some point in the middle, suspect the part
(s) you added at that point.  These days such a problem is typically
handled by replacing the mainboard at a repair shop, then if that
doesn't work they replace the next part and so on, till it's fixed or
the customer refuses to pay for their diagnosed problem since often
the laptop cost little more than the total repair cost.

Had a problem like that with an old Dell laptop. Measuring the
resistance across the power input jack showed a direct short. After
disassembling the unit I found an electrolytic across the power lines,
after the rf filter & fuse that was shorted. Removed it and the laptop
now works fine (so much for no electrolytics in laptops).

        Jerry

Now you know one of the reasons why they don't typically put
electrolytics in laptops anymore. I never suggested no old laptop
ever had any, but this is a pretty modern laptop not some ancient Dell.

Considering the size it was probably a tantalum, which is a *type* of
electrolytic capacitor.

Considering the Dell is by now probably 12 years old I'd say it's
doing quite well.

Jerry

 

[bz]

emailaddress@insightbb.com wrote in news:d972e65d-ba83-4734-b5b7-
1b55bd8d4ef1@k19g2000prh.googlegroups.com:

Nope. There are wet tantalum capacitors (that exist), but nobody uses
those in laptops. In laptops you find surface mount dry tantalums
among other solid types, not electrolytic at all... again, this refers
to semi-modern laptops, not something really ancient.

http://en.wikipedia.org/wiki/Electrolytic_capacitor

Take a look at the pictures.
http://en.wikipedia.org/wiki/File:Cap-elko-smd-polarity.jpg

Check your laptop and make sure you DON'T have any of the mugs in the shot.

If you are saying that 'modern' laptops don't have
http://en.wikipedia.org/wiki/File:Capacitors_electrolytic.jpg
then you are right but modern laptops DO have other types of electrolytic.

The defining part that makes a capacitor an electrolytic is the presence of
an electrolyte and the electro-chemical reaction that forms one of the
electrodes in 'very close proximity' to the metal electrode which can be
aluminum or tantalum or some other metal.

I used to make ceramic capacitors, so I am not really an expert on
electrolytic but you seem to have a mistaken idea as to what constitutes an
'electrolytic'.




--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[krw]

In article <vVjnl.387314$Mh5.177109@bgtnsc04-
news.ops.worldnet.att.net>, jerry@example.invalid says...>

In sci.electronics.repair Conor <conor_turton@hotmail.com> wrote:
In article <Xns9BB7430C6B726WQAHBGMXSZHVspammote@130.39.198.139>, bz
says...

emailaddress@insightbb.com wrote in news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f5ef@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to top edge and ~1/8
distance to right edge, with brown polarity bands, opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top edge center and two
near the bottom edge center, partially hidden by a wiring bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.

Any cap over .1 uF or so will probably be an electro.

Nah, ceramics up to (and including) 10uF are common. I use bunches
of 'em. There's quite an overlap (both have their use).

 

[Baron]

emailaddress@insightbb.com wrote:

On Feb 18, 6:20 pm, Jerry Peters <je...@example.invalid> wrote:
In sci.electronics.repair emailaddr...@insightbb.com wrote:
On Feb 18, 1:09 am, jakdedert <jakded...@bellsouth.net> wrote:
Conor wrote:
In article <p5jmp4tnc8bi0ql9044d8uo4uons77m...@4ax.com>, Rich
Webb says...

Perhaps the plague? No, not THAT one, THIS one:
http://en.wikipedia.org/wiki/Capacitor_plague

Worth eyeballing since you already have the main board exposed.

Didn't think laptops used electrolytic capacitors...

They're surface mount, so you might not recognize them.  Google is
your friend....

Yes, but, although surface mount caps can be electrolytic, in a
notebook (none at all if it's a good design), very few caps are
electrolytic, if any, except in the external brick AC-DC PSU.

That's complete nonsense, of course a laptop uses electrolytics, and
lots of them to filter power throughout the unit. As jakedart said
they're surface mount units. Take one apart sometime & look.

Jerry

I have, several times. They use mostly if not entirely solid,
(usually chip) caps, and ceramics with good reason. Electrolytics
wear out too fast inside modern laptops because of the elevated temps,
not to mention their height being a problem when engineering something
as thin as reasonably possible.

Here's a picture of both sides of a quite typical HP laptop mainboard,
under two years old and quite similar to what they're still using.
Point out the electrolytic caps on it and BTW, this is the whole thing
there is no separate power board:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

There are six visible in fz3.jpg

http://img243.imageshack.us/img243/961/bottomsmsf5.jpg

and four, possibly five in sf5.jpg

The solid caps are black, and yellow.

Those two are tants and I think the others are too !

The ceramics of course are tan.
There are plenty more pictures from 3rd parties available with a
google search if you can't accept the above pics are typical:
http://images.google.com/images?q=laptop+mainboard

--
Best Regards:
Baron.

 

[Baron]

emailaddress@insightbb.com wrote:

On Feb 19, 12:19 am, emailaddr...@insightbb.com wrote:
... BTW, this is the whole thing
there is no separate power board:

By that I meant no internal power converter board that's separate, it
does have a separate input jack board (also without caps, it's only a
strip big enough to hold a couple jacks), and the brick AC-DC adapter
separate as with practically all laptops in the last several years.

There is a switch mode PSU in the first picture bottom right hand side
along with its four caps and inductor !

--
Best Regards:
Baron.

 

On Feb 19, 3:24 pm, bz <bz+...@ch100-5.chem.lsu.edu> wrote:

emailaddr...@insightbb.com wrote in news:d972e65d-ba83-4734-b5b7-
1b55bd8d4...@k19g2000prh.googlegroups.com:

Nope.  There are wet tantalum capacitors (that exist), but nobody uses
those in laptops.  In laptops you find surface mount dry tantalums
among other solid types, not electrolytic at all... again, this refers
to semi-modern laptops, not something really ancient.

http://en.wikipedia.org/wiki/Electrolytic_capacitor

Take a look at the pictures.http://en.wikipedia.org/wiki/File:Cap-elko-smd-polarity.jpg

Check your laptop and make sure you DON'T have any of the mugs in the shot.

If you are saying that 'modern' laptops don't havehttp://en.wikipedia.org/wiki/File:Capacitors_electrolytic.jpg
then you are right but modern laptops DO have other types of electrolytic..

The defining part that makes a capacitor an electrolytic is the presence of
an electrolyte and the electro-chemical reaction that forms one of the
electrodes in 'very close proximity' to the metal electrode which can be
aluminum or tantalum or some other metal.

I used to make ceramic capacitors, so I am not really an expert on
electrolytic but you seem to have a mistaken idea as to what constitutes an
'electrolytic'.

http://www.hitachi-aic.com/english/products/capacitors/tantal/k_chip.html

Not electrolyte in the conventional sense of the word.
While we could (and are) technically arguing about what constitutes an
electrolyte, the majority of the capacitor industry is calling
electrolytic caps those that have a liquid solvent. A few may have
caused confusion because when they claim electrolytic they are not
talking about the same thing, they are only referring to the
manufacturing process in which they grow the oxide layer on the metal
using electrolyte which is not put in the capacitor as a finished
product.

 

On Feb 19, 4:16 pm, Jerry Peters <je...@example.invalid> wrote:

In sci.electronics.repair emailaddr...@insightbb.com wrote:
On Feb 18, 6:25 pm, Jerry Peters <je...@example.invalid> wrote:
In sci.electronics.repair emailaddr...@insightbb.com wrote:
On Feb 17, 6:35 pm, "tg" <t...@nospamevereverever.net> wrote:
I have a Compaq laptop Model Presario, service tag C300EA that will not
start. It's this one:http://www.microdevices.lk/images/Laptop.jpg
the motherboard is an IBL30 LA-3324P and they retail for about Ł125.
ouch
The problem is when I plug a power supply into it and press the on/off
button the power led flashes rapidly for a few seconds and then cuts
out. I then have to wait about a minute before it will light up again.
I've tried three different power supplies, one of them coming from a
battery/voltage converter and all three power supplies produce the same
fault on the laptop so it's not the power supply. It acts the same with
or without a battery fitted. When the power supply is plugged in I did
notice the battery icon flickers all the time with no battery in.
I also connected an amp meter to the power supply and when the power
light does flicker there is virtually no current draw into the laptop.
I split the chassis to take a look and saw that the power socket wires
go straight onto the motherboard. There is no power board or
daughtercard as such..
does anyone have an idea if there's a known component that causes this
problem? or is it a case of new motherboard?
thanks for any pointers.

The symptoms suggest a short on the mainboard, the PSU aren't able to
regulate so their protection circuits are cycling them off as best
they can (at the price-point of the design).

There isn't much you can do at this point except strip the mainboard
down as much as possible.  Disconnect hard drive, optical, memory, CPU
(except if you take the heatsink off and it was heatsinking the
chipset, you must put that heatsink back on and ensure it makes good
contact with the chipset still), card reader, screen, inverter board..
See if it will then "seem" (since you have no screen, watch the power
LED(s)) to stay on.  It may not, without a processor and memory.  If
necessary put those back in and retry.  If it stays on, reconnect
screen but not the backpanel lighting inverter yet.  If it turns on
and stays on, see if there is output to the screen by shining a strong
flashlight on it.

If it works this far, an inverter failure is a common cause.  If it
didn't work at all up to this point, mainboard probably needs
replaced.  If it works up to some point in the middle, suspect the part
(s) you added at that point.  These days such a problem is typically
handled by replacing the mainboard at a repair shop, then if that
doesn't work they replace the next part and so on, till it's fixed or
the customer refuses to pay for their diagnosed problem since often
the laptop cost little more than the total repair cost.

Had a problem like that with an old Dell laptop. Measuring the
resistance across the power input jack showed a direct short. After
disassembling the unit I found an electrolytic across the power lines,
after the rf filter & fuse that was shorted. Removed it and the laptop
now works fine (so much for no electrolytics in laptops).

        Jerry

Now you know one of the reasons why they don't typically put
electrolytics in laptops anymore.  I never suggested no old laptop
ever had any, but this is a pretty modern laptop not some ancient Dell.

Considering the size it was probably a tantalum, which is a *type* of
electrolytic capacitor.

Considering the Dell is by now probably 12 years old I'd say it's
doing quite well.

        Jerry

Yes that's a great life for a laptop but at what point do you have to
build your own battery packs because even the new stock is several
years old stock?

It was not likely a tantalum, you do realize they explode, not vent,
when shorted or reverse polarity? Not sure about the wet ones
(probably not), but there's no reason they'd use something that exotic
on the DC power inlet filter.

 

On Feb 19, 4:10 pm, Jerry Peters <je...@example.invalid> wrote:

In sci.electronics.repair Conor <conor_tur...@hotmail.com> wrote:

In article <Xns9BB7430C6B726WQAHBGMXSZHVspamm...@130.39.198.139>, bz
says...

emailaddr...@insightbb.com wrote in news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f...@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to top edge and ~1/8
distance to right edge, with brown polarity bands, opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top edge center and two
near the bottom edge center, partially hidden by a wiring bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.

Any cap over .1 uF or so will probably be an electro.

        Jerry

No. You can easily see on cap manufacturer datasheets that almost all
chip caps are not electrolytic, and even ceramics now go up to 20uF.
The chip tantalum, niobium, and other solid polymer caps you'll often
find in laptops typically go up to about 470uF, there have been great
strides in the past few years in this respect.

 

On Feb 19, 4:13 pm, Jerry Peters <je...@example.invalid> wrote:

In sci.electronics.repair emailaddr...@insightbb.com wrote:
On Feb 19, 10:57 am, "David" <some...@somewhere.com> wrote:
"Conor" <conor_tur...@hotmail.com> wrote in message

news:705dd7Fn2gvcU3@mid.individual.net...

In article
Xns9BB7430C6B726WQAHBGMXSZHVspamm...@130.39.198.139>, bz
says...

emailaddr...@insightbb.com wrote in
news:f8d97d59-d8dc-4594-8cd4-
8aef8e72f...@z10g2000prl.googlegroups.com:

http://img242.imageshack.us/img242/5075/topsmfz3.jpg

Two light tan, near left bottom corner, ~1/4 distance to
top edge and ~1/8
distance to right edge, with brown polarity bands,
opposite polarity, bands
out.

Without part numbers, it's meaningless.

I see at least 3 on the bottom view, one near the top
edge center and two
near the bottom edge center, partially hidden by a wiring
bundle.

Any cap over 10 uF will probably be electrolytic.

Wrong.

--
Conor

Actually most laptops use tantalum polarized capacitors
which are a type of electrolytic capacitor. What they avoid
are the more common aluminum electrolytic capacitors.
Ceramics are available in low voltages at quite high
capacitance values, but I have yet to see one over 10 uF.

David

Nope.  There are wet tantalum capacitors (that exist), but nobody uses
those in laptops.  In laptops you find surface mount dry tantalums
among other solid types, not electrolytic at all... again, this refers
to semi-modern laptops, not something really ancient.

A tatalum cap is a type of electrolytic. Specifically the dielectric
is formed by electro-chemical action.

        Jerry

There are types of wet tantalums that are electrolytic caps, but the
solid tantalums are not. Where are these urban myths coming from?

 

On Feb 19, 3:24 pm, bz <bz+...@ch100-5.chem.lsu.edu> wrote:

emailaddr...@insightbb.com wrote in news:d972e65d-ba83-4734-b5b7-
1b55bd8d4...@k19g2000prh.googlegroups.com:

Nope.  There are wet tantalum capacitors (that exist), but nobody uses
those in laptops.  In laptops you find surface mount dry tantalums
among other solid types, not electrolytic at all... again, this refers
to semi-modern laptops, not something really ancient.

http://en.wikipedia.org/wiki/Electrolytic_capacitor

Take a look at the pictures.http://en.wikipedia.org/wiki/File:Cap-elko-smd-polarity.jpg

Check your laptop and make sure you DON'T have any of the mugs in the shot.

If you are saying that 'modern' laptops don't havehttp://en.wikipedia.org/wiki/File:Capacitors_electrolytic.jpg
then you are right but modern laptops DO have other types of electrolytic..

The defining part that makes a capacitor an electrolytic is the presence of
an electrolyte and the electro-chemical reaction that forms one of the
electrodes in 'very close proximity' to the metal electrode which can be
aluminum or tantalum or some other metal.

I used to make ceramic capacitors, so I am not really an expert on
electrolytic but you seem to have a mistaken idea as to what constitutes an
'electrolytic'.

--
bz      73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+...@ch100-5.chem.lsu.edu   remove ch100-5 to avoid spam trap

This is a good example of why we can't trust the encyclopedia that
anyone can edit.
The pictured caps aren't all electrolytic. The first two from the
left are, and the rest are not (not 100% sure about the 2nd from the
end on the right side).

Electrolytic requires liquid electrolyte.

 

[bz]

emailaddress@insightbb.com wrote in news:58f338af-65bf-42a4-b96e-
13470dae805c@g3g2000pre.googlegroups.com:

On Feb 19, 3:24 pm, bz <bz+...@ch100-5.chem.lsu.edu> wrote:
emailaddr...@insightbb.com wrote in news:d972e65d-ba83-4734-b5b7-
1b55bd8d4...@k19g2000prh.googlegroups.com:

Nope.  There are wet tantalum capacitors (that exist), but nobody use
s
.....
The defining part that makes a capacitor an electrolytic is the presence
of
an electrolyte and the electro-chemical reaction that forms one of the
electrodes in 'very close proximity' to the metal electrode which can be
aluminum or tantalum or some other metal.

I used to make ceramic capacitors, so I am not really an expert on
electrolytic but you seem to have a mistaken idea as to what constitutes
an
'electrolytic'.
.....

This is a good example of why we can't trust the encyclopedia that
anyone can edit.
The pictured caps aren't all electrolytic. The first two from the
left are, and the rest are not (not 100% sure about the 2nd from the
end on the right side).

Electrolytic requires liquid electrolyte.

READ the article.
http://en.wikipedia.org/wiki/Electrolytic_capacitor
I see no mistakes in it.

YOU are mistaken in your idea that electrolytics require a liquid
electrolyte.

You will find that the essential action that produces an electrolytic is the
formation of the dielectric 'oxide' layer by the electrochemical action.

There is no point in arguing over a definition. One either accept the
commonly used definition and communicates with the world or insists on using
a different definition and is frequently misunderstood.

Electrolyte: An electrolyte is a substance that will dissociate into ions in
solution and acquire the capacity to conduct electricity. The electrolytes
include sodium, potassium, chloride, calcium and phosphate. Informally,
called lytes. (The clue to the word electrolyte is in the lyte which comes
from the Greek lytos meaning that may be dissolved.)
[unquote]

If you look up "solid electrolyte" you will find that there are many
compounds that are considered electrolytes that contain no water and some are
even solids.

The SM chip left of C34 is probably an electrolytic, as are the two above the
marking C518 on the topside picture. On the bottom, the two chips I mentioned
before are just to the right and above the marking R678, another is above the
marking 07/03/17 on the heat pipe in your bottom picture.

But we have wandered far afield of helping the OP fix the problem with his
laptop.





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap