sci.electronics.repair - 21 new messages in 9 topics - digest

sci.electronics.repair
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Today's topics:

==============================================================================
TOPIC: avr-2700 service manual
http://groups.google.com/group/sci.electronics.repair/t/2c0ce7821fc95206?hl=en
==============================================================================

== 1 of 2 ==
Date: Thurs, Aug 26 2010 12:49 am
From: Max Harding vk3jin

http://elektrotanya.com/denon_dcd-2700.pdf/download.html

== 2 of 2 ==
Date: Thurs, Aug 26 2010 8:02 am
From: sam@repairfaq.org (Samuel M. Goldwasser)

Max Harding vk3jin <maxh10@optusnet.com.au> writes:

> http://elektrotanya.com/denon_dcd-2700.pdf/download.html

Thanks but that's a CD player. :)

--
sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

==============================================================================
TOPIC: Denon AVR-2700 Stuck in Standby
http://groups.google.com/group/sci.electronics.repair/t/36ac2e68890690bc?hl=en
==============================================================================

== 1 of 5 ==
Date: Thurs, Aug 26 2010 2:20 am
From: "Mark Zacharias"

"Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message
news:uaaoawuib.fsf@repairfaq.org...
> This receiver worked perfectly :) until today. Pushing main power button
> (a hard switch) results in the Standy and Lock LEDs turning on and nothing
> else. No controls have any effect. No response from remote.
>
> Main power transformer never receives any power, two fuses on mainboard
> test good.
>
> Any suggestions or service manual/schematics appreciated.
>
> Thanks!
>
> --
> sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
> Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
> +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
> | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html
>
> Important: Anything sent to the email address in the message header above
> is
> ignored unless my full name AND either lasers or electronics is included
> in the
> subject line. Or, you can contact me via the Feedback Form in the FAQs.
>
>

If you'd like to email me at

mark_zacharias@labolgcbs.net

notice the underscore "_" and reverse the domain to read "sbcglobal.net" I
can e-mail you the manual in .RAR chunks for reassembly on your end.
Please specify the size of attachments you can take, 8 meg or whatever.

Does it go back to standby and blink the power LED or not even respond to
pressing the power standby button?

There could be a "secret decoder ring" reset procedure to unlock it after a
protect mode has been triggered. This is increasingly common.

Mark Z.

== 2 of 5 ==
Date: Thurs, Aug 26 2010 2:32 am
From: "Mark Zacharias"

"Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message
news:u62yywgv9.fsf@repairfaq.org...
> "David Farber" <farberbear.unspam@aol.com> writes:
>
>> Samuel M. Goldwasser wrote:
>> > This receiver worked perfectly :) until today. Pushing main power
>> > button (a hard switch) results in the Standy and Lock LEDs turning on
>> > and nothing else. No controls have any effect. No response from
>> > remote.
>> >
>> > Main power transformer never receives any power, two fuses on
>> > mainboard test good.
>> >
>> > Any suggestions or service manual/schematics appreciated.
>> >
>> > Thanks!
>>
>> Here's the manual:
>> http://www.eserviceinfo.com/downloadsm/26005/Denon_AVR-2700.html
>
> Thanks, but unfortunately while it says service manual, it's only the
> user manual.
>
> --
> sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
> Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
> +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
> | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html
>
> Important: Anything sent to the email address in the message header above
> is
> ignored unless my full name AND either lasers or electronics is included
> in the
> subject line. Or, you can contact me via the Feedback Form in the FAQs.

I downloaded the manuals - there is a reset (initalization) procedure.

Press and hold the STEREO and DIRECT buttons while pressing the main power
switch. When the display segments all light up and flash at 1 second
intervals you can release the buttons.
These types of mysterious lockups used to be extremely common on some Denon
models. Actually, it's still fairly common...

Mark Z.

== 3 of 5 ==
Date: Thurs, Aug 26 2010 8:05 am
From: sam@repairfaq.org (Samuel M. Goldwasser)

"Mark Zacharias" <mark_zacharias@sbcglobal.net> writes:

> "Samuel M. Goldwasser" <sam@repairfaq.org> wrote in message
> news:uaaoawuib.fsf@repairfaq.org...
> > This receiver worked perfectly :) until today. Pushing main power button
> > (a hard switch) results in the Standy and Lock LEDs turning on and nothing
> > else. No controls have any effect. No response from remote.
> >
> > Main power transformer never receives any power, two fuses on mainboard
> > test good.
> >
> > Any suggestions or service manual/schematics appreciated.
> >
> > Thanks!
> >
> > --
> > sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/

> If you'd like to email me at
>
> mark_zacharias@labolgcbs.net

I will email you.

> notice the underscore "_" and reverse the domain to read
> "sbcglobal.net" I can e-mail you the manual in .RAR chunks for
> reassembly on your end.
> Please specify the size of attachments you can take, 8 meg or whatever.
>
> Does it go back to standby and blink the power LED or not even respond
> to pressing the power standby button?

Only the main power (hard) switch has an effect - to turn on the
Standby and Lock LEDs.

There is no response to any other buttons.

The power transformer never gets voltage, even for an instant.

> There could be a "secret decoder ring" reset procedure to unlock it
> after a protect mode has been triggered. This is increasingly common.

We have tried the STEREO and DIRECT buttons at the same time while
turning on power - no effect.

Thanks!

== 4 of 5 ==
Date: Thurs, Aug 26 2010 12:38 pm
From: jeanyves

On 2010-08-25 22:58:10 +0200, sam@repairfaq.org (Samuel M. Goldwasser) said:

> jeanyves <no-pub-for-jypochez@free.fr> writes:
>
>> On 2010-08-25 18:02:20 +0200, sam@repairfaq.org (Samuel M. Goldwasser) said:
>>
>>> This receiver worked perfectly :) until today. Pushing main power button
>>> (a hard switch) results in the Standby and Lock LEDs turning on and nothing
>>> else. No controls have any effect. No response from remote.
>>> Main power transformer never receives any power, two fuses on
>>> mainboard test good.
>
>>> Any suggestions or service manual/schematics appreciated.
>>> Thanks!
>
>> hi,
>> for me it was one of the main npn transistor 2SD2560 or equivalent
>> that was burned
>> and also the two 0.22 ohms/ 2W resistor near that transistor
>>
>> the main units of denon amplifiers are often almost the same
>> you can get a 2105 or 2106 schematic easyly on the net.
>>
>> hope this helps
>
> This was for symptoms similar to mine?
>
> Thanks!

hi,
yes the symptoms where completely similar (almost)

I bought a 2105 denon on second hand
it worked but I found the central voice not working
I opened it , and found components not soldered on the central voice !!!!
so I resoldered them, and I got the red led and power down...
after desoldering, examining, I found the transistor and 2 resistor bad
replaced them, and everything ok now.

afterwards, I found the schematics of some denon amplifiers on the net
and found all the main units very similar in all the schematics
and also found a lot of same broken units for sale on ebay ...

hope this helps

--
-
Jean-Yves

== 5 of 5 ==
Date: Thurs, Aug 26 2010 4:55 pm
From: sam@repairfaq.org (Samuel M. Goldwasser)

jeanyves <no-pub-for-jypochez@free.fr> writes:

> On 2010-08-25 22:58:10 +0200, sam@repairfaq.org (Samuel M. Goldwasser) said:
>
> > jeanyves <no-pub-for-jypochez@free.fr> writes:
> >
> >> On 2010-08-25 18:02:20 +0200, sam@repairfaq.org (Samuel M. Goldwasser) said:
> >>
> >>> This receiver worked perfectly :) until today. Pushing main power button
> >>> (a hard switch) results in the Standby and Lock LEDs turning on and nothing
> >>> else. No controls have any effect. No response from remote.
> >>> Main power transformer never receives any power, two fuses on
> >>> mainboard test good.
> >
> >>> Any suggestions or service manual/schematics appreciated.
> >>> Thanks!
> >
> >> hi,
> >> for me it was one of the main npn transistor 2SD2560 or equivalent
> >> that was burned
> >> and also the two 0.22 ohms/ 2W resistor near that transistor
> >> the main units of denon amplifiers are often almost the same
> >> you can get a 2105 or 2106 schematic easyly on the net.
> >> hope this helps
> > This was for symptoms similar to mine?
> > Thanks!
>
> hi,
> yes the symptoms where completely similar (almost)
>
> I bought a 2105 denon on second hand
> it worked but I found the central voice not working
> I opened it , and found components not soldered on the central voice !!!!
> so I resoldered them, and I got the red led and power down...
> after desoldering, examining, I found the transistor and 2 resistor bad
> replaced them, and everything ok now.
>
> afterwards, I found the schematics of some denon amplifiers on the net
> and found all the main units very similar in all the schematics
> and also found a lot of same broken units for sale on ebay ...
>
> hope this helps

Interesting.... Mark Z found the service manual so that at least should help.

I should note though that this unit never attempts to power up at all - only
the Standby and Lock LEDs come on. There is never any voltage to the power
transformer, not even for an instant. No clicking relay, no response
from the remote. No response to the reset (STEREO and DIRECT pressed while
turning on power).

Thanks!

==============================================================================
TOPIC: Best solder free electrical connection
http://groups.google.com/group/sci.electronics.repair/t/11e5e6461418f740?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Aug 26 2010 3:45 am
From: salty@dog.com

On Wed, 25 Aug 2010 18:28:14 -0500, "krw@att.bizzzzzzzzzzzz"
<krw@att.bizzzzzzzzzzzz> wrote:

>On Wed, 25 Aug 2010 08:10:58 -0400, salty@dog.com wrote:
>
>>On Tue, 24 Aug 2010 22:51:21 -0500, "krw@att.bizzzzzzzzzzzz"
>><krw@att.bizzzzzzzzzzzz> wrote:
>>
>>>On Tue, 24 Aug 2010 06:18:42 -0400, salty@dog.com wrote:
>>>
>>>>On Mon, 23 Aug 2010 20:26:51 -0500, "krw@att.bizzzzzzzzzzzz"
>>>><krw@att.bizzzzzzzzzzzz> wrote:
>>>>
>>>>>On Mon, 23 Aug 2010 19:39:56 -0400, salty@dog.com wrote:
>>>>>
>>>>>>On Mon, 23 Aug 2010 17:48:48 -0400, "Michael A. Terrell"
>>>>>><mike.terrell@earthlink.net> wrote:
>>>>>>
>>>>>>>
>>>>>>>salty@dog.com wrote:
>>>>>>>>
>>>>>>>> On Mon, 23 Aug 2010 15:47:52 -0400, "Michael A. Terrell"
>>>>>>>> <mike.terrell@earthlink.net> wrote:
>>>>>>>>
>>>>>>>> >
>>>>>>>> >Phil Hobbs wrote:
>>>>>>>> >>
>>>>>>>> >> Dave wrote:
>>>>>>>> >> > On 22/08/2010 02:08, Michael A. Terrell wrote:
>>>>>>>> >> >
>>>>>>>> >> >> It was a fast plane, but a poor design.
>>>>>>>> >> >
>>>>>>>> >> > Fast it was, but poor design NO.
>>>>>>>> >> >
>>>>>>>> >> >> They spent wads of money to
>>>>>>>> >> >> build and maintain them, then junked the entire fleet. It was noisy and
>>>>>>>> >> >> very fuel inefficient.
>>>>>>>> >> >
>>>>>>>> >> > As is any super fast jet. I should know, I spent many years working in
>>>>>>>> >> > that environment.
>>>>>>>> >> >
>>>>>>>> >> >> That forced the fares so high that they weren't
>>>>>>>> >> >> able to compete with better planes from multiple countries.
>>>>>>>> >> >
>>>>>>>> >> > Lots of passengers enjoyed the fact they could spend the day shopping in
>>>>>>>> >> > another continent and be home for tea.
>>>>>>>> >> >
>>>>>>>> >> > Dave
>>>>>>>> >> Oh, come on. Anything designed in England in the 1960s has to leak oil.
>>>>>>>> >
>>>>>>>> >
>>>>>>>> > Even their lightbulbs.
>>>>>>>>
>>>>>>>> Many years ago in a previous life, radio host Don Imus brought me his
>>>>>>>> Triumph Motorcycle to look at because the headlight as in fact,
>>>>>>>> leaking oil!
>>>>>>>>
>>>>>>>> Long story short: Bad oil pressure sending unit had it's wire lead
>>>>>>>> encased in a plastic spaghetti tube that ran up along the frame to the
>>>>>>>> headlight housing. Oil was running up through the spaghetti tubing and
>>>>>>>> collecting in the headlight housing. When he parked, it would drip
>>>>>>>> out.
>>>>>>>
>>>>>>>
>>>>>>> One look at Imus, and you knew it wasn't hair oil. ;-)
>>>>>>
>>>>>>He was very well lubricated, himself, back when I knew him.
>>>>>
>>>>>But not with oil. He used white, dry, "lubricant". THat was when he was
>>>>>funny.
>>>>
>>>>He was drinking copious quantities of vodka in those days, and he
>>>>wasn't all that funny in person. In fact, he was quite rude and
>>>>unpleasant. His then wife, Harriet, however was a sweetheart, and some
>>>>of his friends were fun to be around.
>>>
>>>I don't doubt you at all. That was the scuttlebutt around NY.
>>
>>I think the cocaine was probably just to perk him up so he could drink
>>more. I didn't really like him very much, as he spent most of his time
>>scowling, and being very rude to everyone. The upside was that his
>>"posse" included some interesting and fun characters. Among them was a
>>fellow named Ben McGowan, who was in (Kawasaki Lets the Good Times
>>Roll) advertising. He was a real character, and always on board for
>>adventure. Another was a young and relatively unknown sports writer
>>named Mike Lupica. He's since become very well known.
>
>IIRC, Mike Lupika was already a sports writer for the NY Post when he was on
>IitM. He went up from there, but hardly an unknown in the NY area.

Not being a big follower of sports, I didn't think of him as well
known at all. Imus used to tease him about being somewhat short. He
was very likable and interesting.

>I always
>thought Charles McCord was the brains in the outfit. Imus was too stoned. I
>remember the time he, on a break, went into the janitor's closet, thinking it
>was the men's room. He was so blotto never knew any better. McCord had to go
>find him. I think that's when he got the "opportunity" in Cleveland.

Really? You were there? LOL!

==============================================================================
TOPIC: Fuchs Plush "good vibrations" reverb foot pedal from 2009
http://groups.google.com/group/sci.electronics.repair/t/674febdf8c46c762?hl=en
==============================================================================

== 1 of 2 ==
Date: Thurs, Aug 26 2010 3:50 am
From: "N_Cook"

"You don't belong here" printed on the overlay- so thats why its fuched.
Proudly says RoHS on the casing, rustling noises at random, so fuched by
RoHS probably, certainly PbF solder. How to get under the scrappy looking
black "conformal" coating. Not epoxy coating as methylated spirit softened
this plasticky coating enough to scrape off with a wooden cocktail stick on
the Main chip Spin FV-1 , nice to see datasheet for this on their site , and
also 5532. Seems suspect solder on a pin of the main chip, from twizzle
sticking. But what is the cleanest way to get the coating off - it hardly
looks pretty as it is, am concerned about meths migrating capilliary fashion
along the pins, to deal with the underlying pbfitis. Chemical reaction
between this black stuff and solder?

== 2 of 2 ==
Date: Thurs, Aug 26 2010 7:05 am
From: "N_Cook"

wire brush in Dremmel then scalpel between pins and then needle, hooked it
off quite cleanly.

==============================================================================
TOPIC: Where to buy thermal fuse?
http://groups.google.com/group/sci.electronics.repair/t/f85534e7513057f6?hl=en
==============================================================================

== 1 of 2 ==
Date: Thurs, Aug 26 2010 8:09 am
From: Smitty Two

In article <i55387$2ge$1@speranza.aioe.org>,
"james" <nospam@nospam.com> wrote:

Radio Shack 270-1321 is a 228C. If you can't find the right fuse, stick
in a bigger one, I say.

== 2 of 2 ==
Date: Thurs, Aug 26 2010 11:12 am
From: PlainBill47@yawho.com

On Wed, 25 Aug 2010 23:57:12 -0700, "james" <nospam@nospam.com> wrote:

>I have a steam mop that has a bad thermal fuse
>
>SFFUSE
>SF188E
>192 degree C
>10A
>250V
>
>Frys and radio shack sell thermal fuse for $1 to $2, unfortunately they are
>all lower temperature rated. I could mail order it, but it's silly to mail
>order a $1 part and pay $5 shipping.
>
>What other local stores are likely to carry thermal fuse?
>
>The fuse is crimped to the other wires. Once I have the replacement, do I
>have to crimp it, or can I solder it? I already have soldering iron but
>don't have crimping tools.

Here you go. $.98 for quantity one.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=317-1139-ND

They only have 1330 in stock. Specify USPS First Class Mail for
shipping. It'll cost about $2.00 for shipping and will be in your
hands in two days.

PlainBill

==============================================================================
TOPIC: FULLY HOT ENTERTAINMENT
http://groups.google.com/group/sci.electronics.repair/t/37b7b075efbca5e8?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Aug 26 2010 9:01 am
From: SRAVANTHI LOVE

KATRINA KAIF BATH ROOM VIDEO

http://hotvideosee.blogspot.com/2010/07/katrina-in-bath.html

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http://hotvideosee.blogspot.com/2010/03/hot-photo-6.html

HOT&SEXY AUNTY IN A ROMANTIC FEEL

http://hotvideosee.blogspot.com/2010/03/hot-photo-3.html

FOR HOT HEROINES PHOTOS

http://hotheroinesphoto.blogspot.com

AISHWARIYARAI HOT EXPOSING PHOTO

http://hotheroinesphoto.blogspot.com/2010/06/aishwariyarai-hot-photo.html

ANKITHA IN A TUB BATH

http://hotheroinesphoto.blogspot.com/2010/06/ankitha-in-tub-bath.html

TO SEE 100 HOT PHOTO GALLERIES

http://hotheroinesphoto.blogspot.com

==============================================================================
TOPIC: * Simple hack to get $5000 to your Paypal account
http://groups.google.com/group/sci.electronics.repair/t/1395d8918f0862b8?hl=en
==============================================================================

== 1 of 2 ==
Date: Thurs, Aug 26 2010 9:44 am
From: paypal cash

* Simple hack to get $5000 to your Paypal account At http://moneyforwarding.co.cc

i have hidden the Paypal Form link in an image. in that website on
Right Side below search box, click on image and enter your name and
Paypal ID.

== 2 of 2 ==
Date: Thurs, Aug 26 2010 9:48 am
From: Meat Plow

On Thu, 26 Aug 2010 09:44:30 -0700, paypal cash wrote:

> * Simple hack to get $5000 to your Paypal account At
> http://moneyXXXXXXXXXXXXX
>
> i have hidden the Paypal Form link in an image. in that website on Right
> Side below search box, click on image and enter your name and Paypal ID.

I'll get right on that! $5000 richer here I come!

--
Live Fast, Die Young and Leave a Pretty Corpse

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

== 1 of 5 ==
Date: Thurs, Aug 26 2010 1:20 pm
From: whit3rd

I recently had a rash of reboot events on my trusty old iMac G5 (1.8
GHz).
This has already had the logic board replaced, as these machines
had some bad-filter-capacitor issues... but this time it was the
capacitors in the power supply, not on the logic board, that
were bulging and leaking electrolyte.

It took an hour or two of catalog work to find low-ESR replacements
for the
nine low-V high-I filter capacitors in the power supply, in form
factors
that would fit the cramped footprint of the originals. So, I thought
I'd relate the parts list here, in case anyone else has need of such
info.

C40 and C52 10V 1000 uF
EKY-100ELL102MH20D

C45, C55 and C56 2200 uF 10V
UHM1A222MPD

C47 16V 1200 uF
UHE1C122MPD

C49 10V 3300 uF
UHN1A332MHD ** this is slightly larger diameter than the
original, but it fits **
UHZ0J332MPM **right size, but less voltage margin**

C59 35V 330 uF
ELXV350ELL331MJ20S

C64 15V 1000 uF
EEU-FC1E102B

These were all in stock at Mouser Electronics, if that matters.

== 2 of 5 ==
Date: Thurs, Aug 26 2010 2:04 pm
From: Meat Plow

On Thu, 26 Aug 2010 13:20:18 -0700, whit3rd wrote:

> I recently had a rash of reboot events on my trusty old iMac G5 (1.8
> GHz).
> This has already had the logic board replaced, as these machines had
> some bad-filter-capacitor issues... but this time it was the capacitors
> in the power supply, not on the logic board, that were bulging and
> leaking electrolyte.
>
> It took an hour or two of catalog work to find low-ESR replacements for
> the
> nine low-V high-I filter capacitors in the power supply, in form factors
> that would fit the cramped footprint of the originals. So, I thought
> I'd relate the parts list here, in case anyone else has need of such
> info.
>
> C40 and C52 10V 1000 uF
> EKY-100ELL102MH20D
>
> C45, C55 and C56 2200 uF 10V
> UHM1A222MPD
>
> C47 16V 1200 uF
> UHE1C122MPD
>
> C49 10V 3300 uF
> UHN1A332MHD ** this is slightly larger diameter than the
> original, but it fits **
> UHZ0J332MPM **right size, but less voltage margin**
>
> C59 35V 330 uF
> ELXV350ELL331MJ20S
>
> C64 15V 1000 uF
> EEU-FC1E102B
>
> These were all in stock at Mouser Electronics, if that matters.

Hell yes it matters. I'm going to fix a year old Coolmax 650 watt PC PSU
and will be looking for some replacement caps. I like to keep a spare and
I need 650 with this new AMD 120 watt quad core PhenomII 3.2 ghz CPU and
Asus M4A78E-T mobo. With Asus overclocking friendly special settings I'm
able to run it at 4.0 ghz for each core. Makes video encoding on an
application supporting multicore encoding really fly. Not unusual to get
over 350 frames/sec out of NTSC 740x480 avi's. I can make a high quality
20 chapter DVD with all the bells and whistles in about an hour. Used to
take 24 hours on a 2ghz single core AMD :)

--
Live Fast, Die Young and Leave a Pretty Corpse

== 3 of 5 ==
Date: Thurs, Aug 26 2010 5:27 pm
From: "Arfa Daily"

"Meat Plow" <mhywatt@yahoo.com> wrote in message
news:pan.2010.08.26.21.04.20@hahahahahahahah.nutz.I.am...
> On Thu, 26 Aug 2010 13:20:18 -0700, whit3rd wrote:
>
>> I recently had a rash of reboot events on my trusty old iMac G5 (1.8
>> GHz).
>> This has already had the logic board replaced, as these machines had
>> some bad-filter-capacitor issues... but this time it was the capacitors
>> in the power supply, not on the logic board, that were bulging and
>> leaking electrolyte.
>>
>> It took an hour or two of catalog work to find low-ESR replacements for
>> the
>> nine low-V high-I filter capacitors in the power supply, in form factors
>> that would fit the cramped footprint of the originals. So, I thought
>> I'd relate the parts list here, in case anyone else has need of such
>> info.
>>
>> C40 and C52 10V 1000 uF
>> EKY-100ELL102MH20D
>>
>> C45, C55 and C56 2200 uF 10V
>> UHM1A222MPD
>>
>> C47 16V 1200 uF
>> UHE1C122MPD
>>
>> C49 10V 3300 uF
>> UHN1A332MHD ** this is slightly larger diameter than the
>> original, but it fits **
>> UHZ0J332MPM **right size, but less voltage margin**
>>
>> C59 35V 330 uF
>> ELXV350ELL331MJ20S
>>
>> C64 15V 1000 uF
>> EEU-FC1E102B
>>
>> These were all in stock at Mouser Electronics, if that matters.
>
> Hell yes it matters. I'm going to fix a year old Coolmax 650 watt PC PSU
> and will be looking for some replacement caps. I like to keep a spare and
> I need 650 with this new AMD 120 watt quad core PhenomII 3.2 ghz CPU and
> Asus M4A78E-T mobo. With Asus overclocking friendly special settings I'm
> able to run it at 4.0 ghz for each core. Makes video encoding on an
> application supporting multicore encoding really fly. Not unusual to get
> over 350 frames/sec out of NTSC 740x480 avi's. I can make a high quality
> 20 chapter DVD with all the bells and whistles in about an hour. Used to
> take 24 hours on a 2ghz single core AMD :)
>
>
>

Just as a matter of interest Meat, what is your preferred brand and type of
heatsink goop when working with these very high power processors? I've
recently been working with some games machines that have two very powerful
processors on the board, and have been having some thermal issues when using
'standard' white silicon grease on them, which appears to be what the
manufacturer used originally. I have today reassembled one using some Arctic
Silver compound instead, and it seems to be doing a fine job. I have always
resisted using this stuff, because it's so messy, and so hard to remove
unless you use the complementary cleaner, but if it really is that much more
effective, then I might be prepared to live with these shortcomings. Anyone
else got any constructive comments on the subject of thermal interfacing of
coolers to high power chips ?

Arfa

== 4 of 5 ==
Date: Thurs, Aug 26 2010 6:23 pm
From: Jeff Liebermann

On Fri, 27 Aug 2010 01:27:14 +0100, "Arfa Daily"
<arfa.daily@ntlworld.com> wrote:

>Anyone
>else got any constructive comments on the subject of thermal interfacing of
>coolers to high power chips ?

In a past life, I used to design HF SSB marine radios. The typical
transmitter was Class AB 150 watts with about 30% efficiency. That's
two devices, dissipating about 125 watts each, over an area of about
70 sq-cm. Oh yes, no fan allowed.

This is quite a bit more dissipation than the average desktop, causing
some things to be more critical. In the process of getting it to
work, I learned a few things.

1. The less silicon grease used, the better. The idea behind silicon
grease is to fill in the gaps, scratches, and gouges in the power
transistor base and aluminum heat sink. Cross sectional
microphotographs show metal to metal contact on the peaks, but huge
gaps, filled with silicon grease, in between. Under ideal
circumstances, maximum metal to metal contact, with minimum gaps is
the target practice.

2. All heat sinks and transistor bases are NOT flat. I made a
dramatic improvement to the measured thermal resistance by polishing
flat the base of the xsistor and the face of the heat sink. That
meant removing the gold from the copper base, but that's what was
necessary. I used a Moire pattern to measure flatness. A mirror
finish was best, but difficult to achieve. To prevent corrosion, I
plated the exposed copper with electroless tin or silver. For the
aluminum heat sink, I just used abrasive polish and a glass polishing
plate to obtain a mirror finish and flat surface.

3. Compression pressure is important. None of the standard spring
clip CPU heat sink holders come even close to optimum. Compression
adjusts for the bends, and also provides some level of galling to
provide metal to metal contact. If done correctly, adding silicon
grease actually increases the thermal resistance. However, this is
difficult to do with a CPU that has components on the bottom side,
thus preventing compression. Applying pressure only on the top center
of the CPU, will cause the substrate to bend, and eventually break. I
have some ideas, but nothing that can be retrofitted to an existing
motherboard and CPU socket. This is close, but not optimum:
<http://www.frostytech.com/articleview.cfm?articleID=2273>
Note the comments on base finish and flatness.

So, if you want the best head sinking, polish flat the CPU top
(removing all the laser scribbled markings, polish the heat sink face,
use very very very very little silicon grease, and compress the
sandwich until it nearly breaks the CPU.

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

== 5 of 5 ==
Date: Fri, Aug 27 2010 12:29 am
From: "N_Cook"

Jeff Liebermann <jeffl@cruzio.com> wrote in message
news:jh3e761hp6mg3b0sb1h6stsdsq19g2mk0m@4ax.com...
> On Fri, 27 Aug 2010 01:27:14 +0100, "Arfa Daily"
> <arfa.daily@ntlworld.com> wrote:
>
> >Anyone
> >else got any constructive comments on the subject of thermal interfacing
of
> >coolers to high power chips ?
>
> In a past life, I used to design HF SSB marine radios. The typical
> transmitter was Class AB 150 watts with about 30% efficiency. That's
> two devices, dissipating about 125 watts each, over an area of about
> 70 sq-cm. Oh yes, no fan allowed.
>
> This is quite a bit more dissipation than the average desktop, causing
> some things to be more critical. In the process of getting it to
> work, I learned a few things.
>
> 1. The less silicon grease used, the better. The idea behind silicon
> grease is to fill in the gaps, scratches, and gouges in the power
> transistor base and aluminum heat sink. Cross sectional
> microphotographs show metal to metal contact on the peaks, but huge
> gaps, filled with silicon grease, in between. Under ideal
> circumstances, maximum metal to metal contact, with minimum gaps is
> the target practice.
>
> 2. All heat sinks and transistor bases are NOT flat. I made a
> dramatic improvement to the measured thermal resistance by polishing
> flat the base of the xsistor and the face of the heat sink. That
> meant removing the gold from the copper base, but that's what was
> necessary. I used a Moire pattern to measure flatness. A mirror
> finish was best, but difficult to achieve. To prevent corrosion, I
> plated the exposed copper with electroless tin or silver. For the
> aluminum heat sink, I just used abrasive polish and a glass polishing
> plate to obtain a mirror finish and flat surface.
>
> 3. Compression pressure is important. None of the standard spring
> clip CPU heat sink holders come even close to optimum. Compression
> adjusts for the bends, and also provides some level of galling to
> provide metal to metal contact. If done correctly, adding silicon
> grease actually increases the thermal resistance. However, this is
> difficult to do with a CPU that has components on the bottom side,
> thus preventing compression. Applying pressure only on the top center
> of the CPU, will cause the substrate to bend, and eventually break. I
> have some ideas, but nothing that can be retrofitted to an existing
> motherboard and CPU socket. This is close, but not optimum:
> <http://www.frostytech.com/articleview.cfm?articleID=2273>
> Note the comments on base finish and flatness.
>
> So, if you want the best head sinking, polish flat the CPU top
> (removing all the laser scribbled markings, polish the heat sink face,
> use very very very very little silicon grease, and compress the
> sandwich until it nearly breaks the CPU.
>
> --
> Jeff Liebermann jeffl@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558

Any opinions on silipads? From my limited trials mica sheet and absolute
minimal white grease has better thermal transfer. Emphasis again on minimal.
Having to decide this week whether to spend out on 6 MJ series TO3 devices
in an old Carver amp failed due to one of the driver TO3 being pushed
through a heap of white grease , so grease on pins getting inside the TO3
socket housing , so insulating partially and eventually burning up the pin .

==============================================================================
TOPIC: Digimate L-1715 inverter part ID needed
http://groups.google.com/group/sci.electronics.repair/t/e7777d19925a9def?hl=en
==============================================================================

== 1 of 1 ==
Date: Thurs, Aug 26 2010 11:56 pm
From: Clyde

Hi. Just got a Digimate 17 inch monitor with no display. Found a bad
shottky diode on the inverter PCB so I replaced that and the fuse, now I
have a screen, however after a few minutes it starts to flicker badly,
on the inverter the transformer on the side I replaced the diode is
getting hot. After a bit of tracing I have found a small SMD (8 pin,
looks like an IC) which is shorted to all pins. I am unable to read the
tiny writing on top and can find no information on what the part is.
Does anyone have any idea, or possibly a schematic. Judging by the way
it is connected (there is an identical one on the other side of the
inverter, dual lamp) I think it may actually be a special kind of zener
diode.

Anyway some numbers, the monitor is a Digimate L-1715 ( I believe the
inverter is used in a variety of other brands ). The inverter PCB is
part number IV185030HX. The part I need is identified as Q3 (maybe a
transistor?)

Can anyone help?

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