sci.electronics.repair@googlegroups.com

Today's topics:

* how to remove alkaline battery residue - 12 messages, 7 authors
http://groups.google.com/group/sci.electronics.repair/t/714a9d09282224a3?hl=en
* vestel 11AK36 A8 TV - PSU not starting - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/40010e9e2ff31ad0?hl=en
* Automotive battery charger circuit breaker. - 4 messages, 3 authors
http://groups.google.com/group/sci.electronics.repair/t/0164462cb92aa394?hl=en
* Yet another bulging-capacitors replacement - 2 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/3ec97de65fce9bb3?hl=en

==============================================================================
TOPIC: how to remove alkaline battery residue
http://groups.google.com/group/sci.electronics.repair/t/714a9d09282224a3?hl=en
==============================================================================

== 1 of 12 ==
Date: Sat, Aug 28 2010 11:39 am
From: "Geoffrey S. Mendelson"

Between the combination of the hotest day in many years and really bad batch
of alkaline batteries, I have several devices with a crystaline residue from
the batteries leaking.

Besides brushing with a succession of stiffer brushes, is there some chemical
that can safely remove it? It's all on metal contacts in plastic, but some are
surrounded by anodized aluminium.

Thanks in advance,

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

== 2 of 12 ==
Date: Sat, Aug 28 2010 1:20 pm
From: "William Sommerwerck"

> Besides brushing with a succession of stiffer brushes,
> is there some chemical that can safely remove it? It's
> all on metal contacts in plastic, but some are surrounded
> by anodized aluminium.

Ordinary household ammonia on a Q-tip with dissolve it. I usually follow
that with an isopropyl alcohol flush.

Possible problem... Aluminum can be attacked by ammonia and other alkaline
solvents. So, be careful.

== 3 of 12 ==
Date: Sat, Aug 28 2010 1:31 pm
From: adrian@poppyrecords.invalid.invalid (Adrian Tuddenham)

William Sommerwerck <grizzledgeezer@comcast.net> wrote:

> > Besides brushing with a succession of stiffer brushes,
> > is there some chemical that can safely remove it? It's
> > all on metal contacts in plastic, but some are surrounded
> > by anodized aluminium.
>
> Ordinary household ammonia on a Q-tip with dissolve it. I usually follow
> that with an isopropyl alcohol flush.
>
> Possible problem... Aluminum can be attacked by ammonia and other alkaline
> solvents. So, be careful.

Plain tap water with a nylon scouring pad seems to work. Alcohol can
then be used to remove the water.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

== 4 of 12 ==
Date: Sat, Aug 28 2010 1:34 pm
From: "Geoffrey S. Mendelson"

William Sommerwerck wrote:

> Ordinary household ammonia on a Q-tip with dissolve it. I usually follow
> that with an isopropyl alcohol flush.
>
> Possible problem... Aluminum can be attacked by ammonia and other alkaline
> solvents. So, be careful.

Thanks, anything else? Ammonia is restricted here. :-(

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

== 5 of 12 ==
Date: Sat, Aug 28 2010 1:39 pm
From: "Geoffrey S. Mendelson"

Adrian Tuddenham wrote:

> Plain tap water with a nylon scouring pad seems to work. Alcohol can
> then be used to remove the water.

Thanks, I'll try that.

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

== 6 of 12 ==
Date: Sat, Aug 28 2010 2:21 pm
From: "ian field"

"Geoffrey S. Mendelson" <gsm@mendelson.com> wrote in message
news:slrni7isgn.hrd.gsm@cable.mendelson.com...
> William Sommerwerck wrote:
>
>> Ordinary household ammonia on a Q-tip with dissolve it. I usually follow
>> that with an isopropyl alcohol flush.
>>
>> Possible problem... Aluminum can be attacked by ammonia and other
>> alkaline
>> solvents. So, be careful.
>
> Thanks, anything else? Ammonia is restricted here. :-(

Isn't acid the opposite of alkaline.......

Such as ordinary acetic acid (vinegar) found in any kitchen.

== 7 of 12 ==
Date: Sat, Aug 28 2010 3:11 pm
From: Jeff Liebermann

On Sat, 28 Aug 2010 20:34:04 +0000 (UTC), "Geoffrey S. Mendelson"
<gsm@mendelson.com> wrote:

>William Sommerwerck wrote:
>
>> Ordinary household ammonia on a Q-tip with dissolve it. I usually follow
>> that with an isopropyl alcohol flush.
>>
>> Possible problem... Aluminum can be attacked by ammonia and other alkaline
>> solvents. So, be careful.
>
>Thanks, anything else? Ammonia is restricted here. :-(
>Geoff.

As long as you don't make any ammonium nitrate fertilizer and diesel
fuel bombs. Be glad that it's restricted because the "ammoniated'
cleaner will streak the anti-reflective coating on some LCD displays.
It's almost impossible to find glass cleaner in the US that does NOt
have ammonia in the formulation.

The electrolyte in alkaline batteries is KOH (potassium hydroxide)
which is NOT very soluable in liquid ammonia. What does the cleaning
in most spray cleaners is n-PropoxyPropanol, which is a form of
alcohol. Looks like 409 spray cleaner has ammonia in the form of
ammonium chloride:
<http://www.thecloroxcompany.com/products/msds/409products/formula409antibacallpurposecleaner807.pdf>

I use 409, Fantastik, or similar cleaner. If it foams when it hits
the KOH, it's working.
<http://www.ehow.com/how_2341688_clean-battery-leakage.html>
<http://www.wikihow.com/Clean-Battery-Leaks/Spills>

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

== 8 of 12 ==
Date: Sat, Aug 28 2010 3:16 pm
From: Jim Yanik

"ian field" <gangprobing.alien@ntlworld.com> wrote in
news:N5feo.132535$S46.76190@hurricane:

>
> "Geoffrey S. Mendelson" <gsm@mendelson.com> wrote in message
> news:slrni7isgn.hrd.gsm@cable.mendelson.com...
>> William Sommerwerck wrote:
>>
>>> Ordinary household ammonia on a Q-tip with dissolve it. I usually
>>> follow that with an isopropyl alcohol flush.
>>>
>>> Possible problem... Aluminum can be attacked by ammonia and other
>>> alkaline
>>> solvents. So, be careful.
>>
>> Thanks, anything else? Ammonia is restricted here. :-(

even household ammonia? sheesh.
>
> Isn't acid the opposite of alkaline.......
>
> Such as ordinary acetic acid (vinegar) found in any kitchen.
>
>
>

vinegar works great. and a lot easier to use than nasty ammonia with it's
fumes.

--
Jim Yanik
jyanik
at
localnet
dot com

== 9 of 12 ==
Date: Sat, Aug 28 2010 3:29 pm
From: "Geoffrey S. Mendelson"

Jeff Liebermann wrote:
>
> As long as you don't make any ammonium nitrate fertilizer and diesel
> fuel bombs. Be glad that it's restricted because the "ammoniated'
> cleaner will streak the anti-reflective coating on some LCD displays.
> It's almost impossible to find glass cleaner in the US that does NOt
> have ammonia in the formulation.

It was restricted because there was a spate of people mixing chlorine bleach
and ammonia to clean their toilet. This is a country of immigrants, and
no one could figure out how to write the warning in enough languages that
it would be safe.

Luckily the glass cleaner here is made with vinegar.

>
> The electrolyte in alkaline batteries is KOH (potassium hydroxide)
> which is NOT very soluable in liquid ammonia. What does the cleaning
> in most spray cleaners is n-PropoxyPropanol, which is a form of
> alcohol. Looks like 409 spray cleaner has ammonia in the form of
> ammonium chloride:
><http://www.thecloroxcompany.com/products/msds/409products/formula409antibacallpurposecleaner807.pdf>

Ok, there are some cleaners like that, and maybe one of those.

> I use 409, Fantastik, or similar cleaner. If it foams when it hits
> the KOH, it's working.
><http://www.ehow.com/how_2341688_clean-battery-leakage.html>
><http://www.wikihow.com/Clean-Battery-Leaks/Spills>

Great, thanks to you and everyone else for the info and the links.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

== 10 of 12 ==
Date: Sat, Aug 28 2010 3:58 pm
From: "William Sommerwerck"

> Ordinary household ammonia on a Q-tip with dissolve it.

Please note that I said "household ammonia". Not ammonia, not ammonium
nitrate fertilizer, not any other form of ammonia. Okay?

Although acids neutralize bases, I don't like the idea of using acids inside
electronic equipment. Acids are more-likely to attack metals than bases.

I've been doing this on and off for years, and never had the least trouble.
Household ammonia, followed by some neutral liquid to wash away anything
that might be left.

== 11 of 12 ==
Date: Sat, Aug 28 2010 5:44 pm
From: Jeff Liebermann

On Sat, 28 Aug 2010 22:29:04 +0000 (UTC), "Geoffrey S. Mendelson"
<gsm@mendelson.com> wrote:

>It was restricted because there was a spate of people mixing chlorine bleach
>and ammonia to clean their toilet. This is a country of immigrants, and
>no one could figure out how to write the warning in enough languages that
>it would be safe.

Teaching them to read Hewbrew would be too expensive? Instead you
get a nation of dirty toilets. I would think that sacrificing a few
immigrants so that the rest could have clean toilets would be a
suitable exchange. I guess international safety symbols won't work
when mixing to non-toxic products. Maybe a toilet with a nuclear
mushroom cloud coming out of the bowl might work.

Well, maybe there's a chemical solution to the problem. Adding any
sulfur compount to the chlorine bleach would be easy. It would be
non-reactive until it hits the ammonia, where it's converted to
ammonium sulfide, which smells like rotten eggs.
<http://en.wikipedia.org/wiki/Stink_bomb>

>Luckily the glass cleaner here is made with vinegar.

I have to make my own for cleaning LCD's. Vinegar, filtered water,
cheap rubbing alcohol, a little dish washing soap (for the wetting
agent), and a few drops of kerosene. There are plenty of similar do
it thyself formulas on the web.

>Great, thanks to you and everyone else for the info and the links.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

== 12 of 12 ==
Date: Sat, Aug 28 2010 10:12 pm
From: "Jerry G."

I use plain water and scrub the surfaces. After, I rub in some contact
cleaner if there are contacts involved.

Jerry G.

On Aug 28, 2:39 pm, "Geoffrey S. Mendelson" <g...@mendelson.com>
wrote:
> Between the combination of the hotest day in many years and really bad batch
> of alkaline batteries, I have several devices with a crystaline residue from
> the batteries leaking.
>
> Besides brushing with a succession of stiffer brushes, is there some chemical
> that can safely remove it? It's all on metal contacts in plastic, but some are
> surrounded by anodized aluminium.
>
> Thanks in advance,
>
> Geoff.
>
> --
> Geoffrey S. Mendelson N3OWJ/4X1GM
> To help restaurants, as part of the "stimulus package", everyone must order
> dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

==============================================================================
TOPIC: vestel 11AK36 A8 TV - PSU not starting
http://groups.google.com/group/sci.electronics.repair/t/40010e9e2ff31ad0?hl=en
==============================================================================

== 1 of 2 ==
Date: Sat, Aug 28 2010 12:17 pm
From: b

On Aug 28, 9:33 am, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
> "b" <reverend_rog...@yahoo.com> wrote in message
>
> news:8f75d703-8667-4259-8068-d91597e86867@q2g2000yqq.googlegroups.com...
>
>
>
> > This 14" 11AK36-A8 tv apparently 'just went off.' there was evidence
> > of a short near the mains inlet, on the print side of the pcb -
> > probably a strand of wire or blob of solder from the time of
> > manufcture had been the cause. checked rectifier, removed PTC in case,
> > replaced fuse. Set dead. 0v at psu o/ps.
>
> > checked the obvious in psu primary,  no shorted diodes or open
> > resistors. Removed secondary diodes including HT line.
>
> > schematics here (5m). Psu is on page 24.:
> >http://www.fileden.com/files/2007/6/4/1143893//11AK36
> > FULL.pdf
>
> > ...not identical but the main aspects are the same.
>
> > 300v present across mains capacitor, and at R821 (safety) and
> > collector of Q801.
> > 25v present at c811, suggesting the uPc of the PSU has power.
>
> > I don't know where to look now. My next step would be to change the
> > uPc UC3843, but I don't think I've ever seen a case where the chip
> > went on its own...
>
> > I should probably have tossed this aside by now but I'm just keen to
> > satisfy my curiosity. So I'm all ears.
> > cheers,
> > B.
>
> The link doesn't seem to get you direct to the schematic. Seems to want a
> login from the home page ?
>
> As for '3843s, I have had them go faulty on their own on other Vestel PSUs,
> but I agree, it's rare. Have you ESR checked any small primary-side
> electrolytics ? Is there anywhere else I can get a squint at the schems, or
> can you mail the pdf to me direct ? I do quite a lot of switchers, and used
> to do a lot of Vestels from bigger LCD TVs, so I might be able to offer an
> insight or two ...
>
> Arfa

thanks. try this link:
http://www.fileden.com/files/2007/6/4/1143893/11AK36%20FULL.pdf

I got this from eserviceinfo originally, I think.
Re: electrolytics, besides the mains filter cap I think there's only
the one I mentioned (c811)
cheers
Ben

== 2 of 2 ==
Date: Sat, Aug 28 2010 4:49 pm
From: "Arfa Daily"

"b" <reverend_rogers@yahoo.com> wrote in message
news:e4159d34-fc6a-4427-800f-17350cf3a391@t20g2000yqa.googlegroups.com...
> On Aug 28, 9:33 am, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
>> "b" <reverend_rog...@yahoo.com> wrote in message
>>
>> news:8f75d703-8667-4259-8068-d91597e86867@q2g2000yqq.googlegroups.com...
>>
>>
>>
>> > This 14" 11AK36-A8 tv apparently 'just went off.' there was evidence
>> > of a short near the mains inlet, on the print side of the pcb -
>> > probably a strand of wire or blob of solder from the time of
>> > manufcture had been the cause. checked rectifier, removed PTC in case,
>> > replaced fuse. Set dead. 0v at psu o/ps.
>>
>> > checked the obvious in psu primary, no shorted diodes or open
>> > resistors. Removed secondary diodes including HT line.
>>
>> > schematics here (5m). Psu is on page 24.:
>> >http://www.fileden.com/files/2007/6/4/1143893//11AK36
>> > FULL.pdf
>>
>> > ...not identical but the main aspects are the same.
>>
>> > 300v present across mains capacitor, and at R821 (safety) and
>> > collector of Q801.
>> > 25v present at c811, suggesting the uPc of the PSU has power.
>>
>> > I don't know where to look now. My next step would be to change the
>> > uPc UC3843, but I don't think I've ever seen a case where the chip
>> > went on its own...
>>
>> > I should probably have tossed this aside by now but I'm just keen to
>> > satisfy my curiosity. So I'm all ears.
>> > cheers,
>> > B.
>>
>> The link doesn't seem to get you direct to the schematic. Seems to want a
>> login from the home page ?
>>
>> As for '3843s, I have had them go faulty on their own on other Vestel
>> PSUs,
>> but I agree, it's rare. Have you ESR checked any small primary-side
>> electrolytics ? Is there anywhere else I can get a squint at the schems,
>> or
>> can you mail the pdf to me direct ? I do quite a lot of switchers, and
>> used
>> to do a lot of Vestels from bigger LCD TVs, so I might be able to offer
>> an
>> insight or two ...
>>
>> Arfa
>
> thanks. try this link:
> http://www.fileden.com/files/2007/6/4/1143893/11AK36%20FULL.pdf
>
> I got this from eserviceinfo originally, I think.
> Re: electrolytics, besides the mains filter cap I think there's only
> the one I mentioned (c811)
> cheers
> Ben

On some of the Vestel supplies that I've worked on, I have had problems with
the high voltage polyester caps going open. That 47nF 630v one, C812, would
be a prime one to check, particularly if it's a bright blue 'boxy' one,
rather than a brown epoxy coated type. I'll have a bit closer look tomorrow.

Arfa

==============================================================================
TOPIC: Automotive battery charger circuit breaker.
http://groups.google.com/group/sci.electronics.repair/t/0164462cb92aa394?hl=en
==============================================================================

== 1 of 4 ==
Date: Sat, Aug 28 2010 1:45 pm
From: PeterD

On Sat, 28 Aug 2010 16:45:08 GMT, Sy <sci_5801@telus.net> wrote:

>Hi.
>Does anyone know where to find a replacement circuit breaker for a 6A automotive
>battery charger?
>
>The charger is from the '70's, a simple basic transformer and 2 diodes . The
>circuit breaker is the type that automatically resets. The old one was a little
>glass tube, but I've seen the type that are square with threaded terminals too.
>Either one would work.
>
>Thanks.

Uh, auto parts store?

== 2 of 4 ==
Date: Sat, Aug 28 2010 3:48 pm
From: "Michael A. Terrell"

Meat Plow wrote:
>
> On Sat, 28 Aug 2010 16:45:08 +0000, Sy wrote:
>
> ? Hi.
> ? Does anyone know where to find a replacement circuit breaker for a 6A
> ? automotive battery charger?
> ?
> ? The charger is from the '70's, a simple basic transformer and 2 diodes .
> ? The circuit breaker is the type that automatically resets. The old one
> ? was a little glass tube, but I've seen the type that are square with
> ? threaded terminals too. Either one would work.
> ?
> ? Thanks.
>
> Google Klixon. They make a wide variety of manual and auto reset DC
> breakers. Only problem is the off time specified by the charger
> manufacturer meaning it needs to stay off for a certain period of time to
> allow the charger electronics to remain under a certain duty cycle.

Klixon was sold off by Texas Insruments long ago to Sensata

http://www.sensata.com

--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

== 3 of 4 ==
Date: Sat, Aug 28 2010 4:13 pm
From: David Nebenzahl

On 8/28/2010 1:45 PM PeterD spake thus:

> On Sat, 28 Aug 2010 16:45:08 GMT, Sy <sci_5801@telus.net> wrote:
>
>> Does anyone know where to find a replacement circuit breaker for a
>> 6A automotive battery charger?
>>
>> The charger is from the '70's, a simple basic transformer and 2
>> diodes. The circuit breaker is the type that automatically resets.
>> The old one was a little glass tube, but I've seen the type that
>> are square with threaded terminals too. Either one would work.
>
> Uh, auto parts store?

I doubt you'd find one there. Most likely just get a blank stare and
"Huh? What?".

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

== 4 of 4 ==
Date: Sat, Aug 28 2010 5:36 pm
From: "Michael A. Terrell"

David Nebenzahl wrote:
>
> On 8/28/2010 1:45 PM PeterD spake thus:
>
> > On Sat, 28 Aug 2010 16:45:08 GMT, Sy <sci_5801@telus.net> wrote:
> >
> >> Does anyone know where to find a replacement circuit breaker for a
> >> 6A automotive battery charger?
> >>
> >> The charger is from the '70's, a simple basic transformer and 2
> >> diodes. The circuit breaker is the type that automatically resets.
> >> The old one was a little glass tube, but I've seen the type that
> >> are square with threaded terminals too. Either one would work.
> >
> > Uh, auto parts store?
>
> I doubt you'd find one there. Most likely just get a blank stare and
> "Huh? What?".

Go to a real auto parts store, not 'Midnight Auto'. Ask for a
headlight circuit breaker. A very common part.

--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

==============================================================================
TOPIC: Yet another bulging-capacitors replacement
http://groups.google.com/group/sci.electronics.repair/t/3ec97de65fce9bb3?hl=en
==============================================================================

== 1 of 2 ==
Date: Sat, Aug 28 2010 5:01 pm
From: "Arfa Daily"

"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns9DE25B60366AAjyaniklocalnetcom@216.168.3.44...
> "Arfa Daily" <arfa.daily@ntlworld.com> wrote in
> news:O24eo.36157$r24.2988@hurricane:
>
>>>> Thanks for the insights Jeff. All interesting stuff. These are
>>>> dedicated games machines, not based on a PC in any way. The power
>>>> supply is specced to deliver 12v at 23 amps, yes, that's twenty
>>>> three amps ...
>>>>
>>>> Almost all of this is potentially going into these two processors,
>>>> so not far off 300 watts between them. No mean task shifting the
>>>> heat off them !
>>>>
>>>> Arfa
>>>>
>>>>
>>>
>>> what processors(microprocessors?) run at 12V?
>>> ISTR that today's uPs run mostly on 3.3V
>>>
>>> Most other digital logic runs at 5V,I believe.
>>>
>>> I think you wil find that most of your power is going into the video
>>> drive (or LCD backlight) circuitry.
>>>
>>> --
>>> Jim Yanik
>>
>>
>> Er no. There are no backlights. Or display processor. These are X-Box
>> / Playstation type boxes. Apart from some support circuitry in IC form
>> - which admittedly does gobble enough power to make it run hot enough
>> that a degree of heatsinking to the pcb shielding via thermal pads is
>> required - everything goes on in a pair of very large BGA processors,
>> one of which is the data processing engine, and the other of which is
>> the graphics processing engine. It is they which make use of the 12v,
>> and they which gobble the amps from it ...
>>
>> The power supply does have other outputs, but these are all at very
>> low current availabilities, so will be for support logic and maybe
>> some core supplies for the two processors. Trust me when I say that
>> the two big chips is where all the power is going, and generating heat
>> that needs shifting
>>:-)
>>
>> Arfa
>>
>>
>
> Odd that BGA processors are using 12V instead of logic level voltages.
>
> I'm surprised they don't use some sort of liquid or heat-pipe plumbing to
> remove all that heat. Wasn't it the CRAYs that used liquid Freon to flood
> the processor cabinet to dissipate al the heat built up?
>
> --
> Jim Yanik

Yes, I was amazed when I read the PSU specs. One of the versions is actually
specced 12v at 32 amps !! The PSU plugs directly onto the board via a pair
of brass pins as thick as those on a power cord for a kettle. The heat is
removed via a pair of flat plates that are connected to a network of sealed
copper pipes, a bit like you see on some Technics amps. I've no idea what is
inside those pipes. This whole assembly is cooled by a centrifugal fan that
idles at a very low speed. The heatsinks have to get up to blisteringly hot
before the processor thinks that it might be a good idea to ramp up the
speed of the fan a bit. I guess they have done this to try and keep the
thing quiet, but personally, I think it is a really poor bit of design. I am
looking at ways to make the fan idle faster, without compromising the auto
ramp up beyond that, when the processor deems it necessary, but
unfortunately, it's not quite as easy as a simple 'analogue OR' function,
because the fan is controlled digitally. It is supplied with a constant 12v,
but a third wire has a PWM signal placed on it by the CPU, and the fan's
internal electronics respond to that to control the speed.

Yes, it was the Cray. It had a central octagonal bus backplane as I recall.
The met office here in the UK used to use one for weather data number
crunching, but I think it has been replaced now.

Arfa

== 2 of 2 ==
Date: Sat, Aug 28 2010 5:03 pm
From: "Arfa Daily"

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:ipednVJmQcLfkOTRnZ2dnUVZ_h6dnZ2d@earthlink.com...
>
> Jim Yanik wrote:
>>
>> Odd that BGA processors are using 12V instead of logic level voltages.
>
>
> Then they would need around 100A at 3.3 volts. The voltage drop
> would be a big problem. I'm sure there is a DC to DC converter near the
> chip, like used on computer motherboards.

Yes indeed Michael. There are in fact 6 of them. Three on each side of the
board ...

Arfa

==============================================================================

You received this message because you are subscribed to the Google Groups "sci.electronics.repair"
group.

To post to this group, visit http://groups.google.com/group/sci.electronics.repair?hl=en

To unsubscribe from this group, send email to sci.electronics.repair+unsubscribe@googlegroups.com

To change the way you get mail from this group, visit:
http://groups.google.com/group/sci.electronics.repair/subscribe?hl=en

To report abuse, send email explaining the problem to abuse@googlegroups.com

==============================================================================
Google Groups: http://groups.google.com/?hl=en