sci.electronics.repair@googlegroups.com

Today's topics:

* Crate BV150H - 3 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/bc73aae36aa34f0a?hl=en
* pops v. cracks in a valve amp - 5 messages, 4 authors
http://groups.google.com/group/sci.electronics.repair/t/b6ee9bc922049d4d?hl=en
* Switching Diode ID required - 7 messages, 6 authors
http://groups.google.com/group/sci.electronics.repair/t/bb0cfa8583047f84?hl=en
* Dead Sony KV-T25SZ8 TV - 3 messages, 3 authors
http://groups.google.com/group/sci.electronics.repair/t/a211bd1fd48660f2?hl=en
* .02 mm pitch flex print PCB repair - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/c0c9b49a40f732fa?hl=en
* How to repair plastic seal for liquids used in human consumption? - 2
messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/13de143057f9156c?hl=en
* motherboard RAM failures - 3 messages, 3 authors
http://groups.google.com/group/sci.electronics.repair/t/3e25b3ae78058770?hl=en

==============================================================================
TOPIC: Crate BV150H
http://groups.google.com/group/sci.electronics.repair/t/bc73aae36aa34f0a?hl=en
==============================================================================

== 1 of 3 ==
Date: Tues, Mar 15 2011 9:17 pm
From: "Phil Allison"

"bored junkies are all losers "

Check plate current directly. Its not a great idea to ballpark bias by
mains current...

** Wrong - as always.

.... Phil

== 2 of 3 ==
Date: Wed, Mar 16 2011 6:39 am
From: boardjunkie1

On Mar 16, 12:17 am, "Phil Allison" <phi...@tpg.com.au> wrote:
> "bored junkies are all losers "
>
> Check plate current directly. Its not a great idea to ballpark bias by
> mains current...
>
> ** Wrong  -  as always.
>
> ....  Phil

Waaaaaaaa! Boo hoo......

Here's Phallison going for the record of biggest douche on Usenet and
he can't even get that right.....

== 3 of 3 ==
Date: Wed, Mar 16 2011 6:09 pm
From: "Phil Allison"

"bored junkies are all losers "

Check plate current directly. Its not a great idea to ballpark bias by
mains current...

** Wrong advice - as always.

.... Phil

==============================================================================
TOPIC: pops v. cracks in a valve amp
http://groups.google.com/group/sci.electronics.repair/t/b6ee9bc922049d4d?hl=en
==============================================================================

== 1 of 5 ==
Date: Wed, Mar 16 2011 2:01 am
From: "N_Cook"

Low frequency pops through the speaker, rather than high frequency cracks.
Would failure of 10,000uF 16V cap on DC balance to the heaters leading to
pops be consistent rather than high V HT cap failure (crack noise).

== 2 of 5 ==
Date: Wed, Mar 16 2011 2:10 am
From: "Phil Allison"

"Nutcase Kook "

> Low frequency pops through the speaker, rather than high frequency cracks.
> Would failure of 10,000uF 16V cap on DC balance to the heaters...

** FFS name the damn amp.

.... Phil

== 3 of 5 ==
Date: Wed, Mar 16 2011 5:21 am
From: boardjunkie1

On Mar 16, 5:01 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> Low frequency pops through the speaker, rather than high frequency cracks.
> Would failure of 10,000uF 16V cap on DC balance to the heaters leading to
> pops be consistent rather than high V HT cap failure (crack noise).

Got a scope? Use it to find where the noise comes from....

== 4 of 5 ==
Date: Wed, Mar 16 2011 6:50 am
From: "N_Cook"

boardjunkie1 <boardjunkie1@gmail.com> wrote in message
news:8bcdbe98-9da3-4667-aacf-81b3f217a11b@n2g2000prj.googlegroups.com...
On Mar 16, 5:01 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> Low frequency pops through the speaker, rather than high frequency cracks.
> Would failure of 10,000uF 16V cap on DC balance to the heaters leading to
> pops be consistent rather than high V HT cap failure (crack noise).

Got a scope? Use it to find where the noise comes from....

&&&&

intermittant, once in an hour or so
By pop = both hands clasped with palms cupped, then clap
crack = 2 fingers laid over the other palm , then clap

== 5 of 5 ==
Date: Wed, Mar 16 2011 9:52 am
From: Meat Plow

On Wed, 16 Mar 2011 13:50:49 +0000, N_Cook wrote:

> boardjunkie1 <boardjunkie1@gmail.com> wrote in message
> news:8bcdbe98-9da3-4667-aacf-81b3f217a11b@n2g2000prj.googlegroups.com...
> On Mar 16, 5:01 am, "N_Cook" <dive...@tcp.co.uk> wrote:
>> Low frequency pops through the speaker, rather than high frequency
>> cracks. Would failure of 10,000uF 16V cap on DC balance to the heaters
>> leading to pops be consistent rather than high V HT cap failure (crack
>> noise).
>
> Got a scope? Use it to find where the noise comes from....
>
> &&&&
>
> intermittant, once in an hour or so
> By pop = both hands clasped with palms cupped, then clap crack = 2
> fingers laid over the other palm , then clap

Have you subbed the valves?

--
Live Fast Die Young, Leave A Pretty Corpse

==============================================================================
TOPIC: Switching Diode ID required
http://groups.google.com/group/sci.electronics.repair/t/bb0cfa8583047f84?hl=en
==============================================================================

== 1 of 7 ==
Date: Wed, Mar 16 2011 5:01 am
From: "Gareth Magennis"

Hi,

trying to find equivalents for a Dual Diode T220F package (insulated tab).
Device is marked RF2001, but can't seem to find a datasheet.

It is from a SMPS and 4 of these rectify the output of the switching
transformer to create the final DC voltages.

I'm not much up on SMPS techology - hate repairng the things - should these
be Shottkys, Ultra fast switching or what?

Cheers,

Gareth.

== 2 of 7 ==
Date: Wed, Mar 16 2011 7:00 am
From: "N_Cook"

Gareth Magennis <sound.service@btconnect.com> wrote in message
news:O8ednVa0RtE3Ox3QnZ2dnUVZ8ludnZ2d@bt.com...
> Hi,
>
> trying to find equivalents for a Dual Diode T220F package (insulated tab).
> Device is marked RF2001, but can't seem to find a datasheet.
>
> It is from a SMPS and 4 of these rectify the output of the switching
> transformer to create the final DC voltages.
>
> I'm not much up on SMPS techology - hate repairng the things - should
these
> be Shottkys, Ultra fast switching or what?
>
>
>
>
> Cheers,
>
> Gareth.
>
>

near enough any old generic dual epitaxial I would have thought , V rating
of caps hints at the minimum V rating and then TO220 suggests the A rating .
Just
which polarity the centre connection , and mica and insulators perhaps if
straight TO220

== 3 of 7 ==
Date: Wed, Mar 16 2011 10:00 am
From: Meat Plow

On Wed, 16 Mar 2011 12:01:33 +0000, Gareth Magennis wrote:

> Hi,
>
> trying to find equivalents for a Dual Diode T220F package (insulated
> tab). Device is marked RF2001, but can't seem to find a datasheet.
>
> It is from a SMPS and 4 of these rectify the output of the switching
> transformer to create the final DC voltages.
>
> I'm not much up on SMPS techology - hate repairng the things - should
> these be Shottkys, Ultra fast switching or what?
>

Schottky diodes are used in many SMPS including but not limited to
chargers (wall wart) adapters and open frame, and PC power supplies.
And are made from various barrier metals and alloys. Some packages
are TO220, TO126, TO247,DO41, DO15 etc...

--
Live Fast Die Young, Leave A Pretty Corpse

== 4 of 7 ==
Date: Wed, Mar 16 2011 3:26 pm
From: whit3rd

Most likely fast-recovery dual diodes. The '2001' might mean
200V and 1A ratings, but that's only a guess. Can you
make out any manufacturer markings other
than that number?

Also, what is the connection? This is probably for an output that is
clearly specified in current rating and output voltage on the
power-supply nameplate.

It might be necessary to use an uninsulated replacement part, with
insulation parts added.

== 5 of 7 ==
Date: Wed, Mar 16 2011 4:47 pm
From: "Phil Allison"

"Gareth Magennis"
>
> trying to find equivalents for a Dual Diode T220F package (insulated tab).
> Device is marked RF2001, but can't seem to find a datasheet.

** You did not look very hard - using " rf2001 diode " the pdf below is the
third hit.

It is NOT in fact a dual diode - dumbass.

http://www.rohm.com/products/databook/di/pdf/rf2001t4s.pdf

.... Phil

== 6 of 7 ==
Date: Wed, Mar 16 2011 6:51 pm
From: "William Sommerwerck"

> It is NOT in fact a dual diode -- dumbass.

You are confusing the poster with a famous French writer. Two, actually --
pere et fils.

== 7 of 7 ==
Date: Wed, Mar 16 2011 7:01 pm
From: "Phil Allison"

"William Sommerwanker"

>> It is NOT in fact a dual diode -- dumbass.
>
> You are confusing the poster with a famous French writer.

** Somebody once made a bunch of money from a song that declared:

" Pablo Picasso was not an asshole "

So, maybe there is a buck to be made from one that says:

" Alexandre Dumas was not a dumbass "

Wadaya think ??

... Phil

==============================================================================
TOPIC: Dead Sony KV-T25SZ8 TV
http://groups.google.com/group/sci.electronics.repair/t/a211bd1fd48660f2?hl=en
==============================================================================

== 1 of 3 ==
Date: Wed, Mar 16 2011 7:35 am
From: "Wild_Bill"

These types of failures are the kinds of problems that TV techs have seen
regularly for a lot of years.. a relatively simple fault is capable of
causing the "smart chassis" type designs to be completely dead, in many
cases.

In sets that develop a fault, and also have some other components that have
changed values due to age, the chassis essentially has compound faults,
which were commonly referred to as Tough Dogs, among other names.
Shut-down circuits have been implemented for many years, to prevent the TV
from operating at all, if the CRT's HV potential exceeded a limit, as a
safety shutdown.

Some minor faults are often complicated by poor soldering during the circuit
board manufacturing process/build, which creates new faults as the boards
age and go thru many thermal cycles.

Many of the electronic equipment designs presently manufactured are similar
designs of smart chassis design, in that one fault will disable every
function.. maybe with the exception of a blinking LED.
In many of these designs, either everything operates within normal limits,
or the units just shut down and won't restart without experienced technical
intervention.

--
Cheers,
WB
.............

"Sylvia Else" <sylvia@not.here.invalid> wrote in message
news:8uaf1cFp84U1@mid.individual.net...
>
> I suppose it's conceivable that since it failed in operation, it always
> tries to power up in that mode, and that the processor won't allow entry
> to standby mode unless everything's working. That would seem a bit
> perverse, but who knows?
>
> Sylvia.

== 2 of 3 ==
Date: Wed, Mar 16 2011 8:11 am
From: "William Sommerwerck"

> In sets that develop a fault, and also have some other
> components that have changed values due to age, the
> chassis essentially has compound faults, which were
> commonly referred to as Tough Dogs, among other names.

The term probably dates back to at least the 30s. It refers to a problem
that refuses to yield to common-sense analysis or trouble-shooting.

== 3 of 3 ==
Date: Wed, Mar 16 2011 9:50 am
From: Meat Plow

On Tue, 15 Mar 2011 15:20:51 -0700, Stroonz wrote:

> On Mar 15, 11:47 am, Meat Plow <mhyw...@yahoo.com> wrote:
>
>
>> You can safely ignore Phil's posts. Most do because of his extreme mood
>> swings and personality disorder.
>>
>> --
>
> On a hunch, I checked the garbage AOL email addy that I use to register
> for public forums, and there (amongst the ton of spam emails) were more
> than a couple of emails offering the same advice. But I'm not
> completely convinced he has mood swings or a personality disorder; I
> suspect he's a typical internet bully who can only demonstrate bravery
> from behind the security of a keyboard. If someone were to act like
> that in real life, you go up to them, grab them by the throat, and watch
> them fill their Pampers. Still, I've often gotten a good laugh from his
> posts.

I've had dialog with Phil that was very helpful and he's even apologized
to me (in his own way) once. On other occasions he's tore into me for no
reason whatsoever. And it's not just me but others that don't do things
the Phil Allison Way. I have no official proof but this behavior smacks
of a sever mental disorder.

--
Live Fast Die Young, Leave A Pretty Corpse

==============================================================================
TOPIC: .02 mm pitch flex print PCB repair
http://groups.google.com/group/sci.electronics.repair/t/c0c9b49a40f732fa?hl=en
==============================================================================

== 1 of 2 ==
Date: Wed, Mar 16 2011 9:42 am
From: "Michael Kennedy"

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:ili9am$opp$1@news.eternal-september.org...
> Michael Kennedy <mikek400@crap.comcast.net> wrote in message
> news:waadnQx_0evQxebQnZ2dnUVZ_gqdnZ2d@giganews.com...
>>
>> "N_Cook" <diverse@tcp.co.uk> wrote in message
>> news:ilfaie$3pr$1@news.eternal-september.org...
>> > Michael Kennedy <mikek400@crap.comcast.net> wrote in message
>> > news:VcydncYKZ9ShC-fQnZ2dnUVZ_q6dnZ2d@giganews.com...
>> >> I have a Plasma tv that somehow I managed to partially tear one of the
>> > flexi
>> >> prints. I am not too sure how it happened since I was working on the
> PSU.
>> >>
>> >> That aside, I think the PSU is fixed, but now the .02 mm pitch flexi
>> >> print
>> >> is torn..
>> >>
>> >> After doing lots of thinking and researching I think the way to go is
>> > using
>> >> a .02mm pitch zebra strip and connect wires from it to the connector.
>> >>
>> >> Now the question is does such a zebra strip exsist?
>> >>
>> >> Does anyone know where I can find such a zebra strip? Any know
>> >> products
> I
>> >> could salvage one from??
>> >>
>> >> I hope to connect wires to the zebra strip and then connect those
>> >> wires
>> >> to
>> >> the more reasonable sized .5mm pitch connector.
>> >>
>> >>
>> >>
>> >
>> > What are the end points of the ribbon ? eg 2 connectors or connector
>> > and
>> > glass ? and does it flex in use? is it microstrip/stripline in
>> > structure
>> > with a grounded backplane?
>>
>>
>> Fortunately there is no backplane, so I think we can get away with
> modified
>> circuit. I will try to get a picture up on the internet soon.
>>
>> The cable is directly connected to the glass on one end and has a
>> standard
>> .5 mm pitch *I think nothing to measure with at the moment* connector.
>>
>>
>> In the middle just after the tear there is a blob IC attached to the
> cable.
>> The cable is then attached to an alunimum plate for security. I was
> thinking
>> of taking advantage of this alunimum plate by using it as a surface to
> mount
>> a zebra connector..
>>
>> The cable is curled in a c like shape so I think briding the original
>> connection is the more dfficult route. I think with a zebra connector and
> a
>> pcb soldering the wires from the end connector to the pcb and the
>> applying
>> pressure to the zebra strip is a very viable solution. There is the
> perfect
>> place to mount it on top of that aluminum plate.
>>
>> Anyhow without pictures this is kind of hard to imagine. I will upload a
> few
>> pics..
>>
>> Thanks for the reply!
>>
>> Mike
>>
>>
>
> Anyone successfully salvaged that expensive 3M anistotrpic conductive
> tape?
> hot air , is that effective to dislodge the bond but not melt the
> tape/destroy the anisotropy?
> I just measured a standard size zebra and that had .2mm spacing, I could
> not
> find my tin of watch bits, what is the spacing on those zebras?
>
>

Thanks for looking. This project is on indefinate hold ATM. I live just
outside Tokyo and you have probably heard the news about the earthquakes
tsunamis and now the nucelar power plant meltdown.

I packed up and ran Monday night. I have moved to the other side of Japan
leaving everythign I own except my car there.

My plans were to to wait till the weekend and see if they get this situation
under control.

I expected that I would be going back to Tokyo this weekend, but I am
starting to think that I will be buying a plane ticket back home to Florida.

As far as I can see the situation went from out of control but possibly
managable to now I would say inevitable major nuclear disaster with a very
good chance of exposure where at my apartment just outside Tokyo.

Thanks for looking into this.. Right now my concerns are on my friends in
Tokyo who dont see the danger and arent leaving. They beleive what the
government is saying that there is no danger. Many people couldnt believe I
was leaving Tokyo for safety and wont listen to my reasoning to leave.

== 2 of 2 ==
Date: Wed, Mar 16 2011 9:50 am
From: "N_Cook"

Michael Kennedy <mike@com> wrote in message
news:HLidnR2ue5HHdR3QnZ2dnUVZ_sidnZ2d@giganews.com...
>
> "N_Cook" <diverse@tcp.co.uk> wrote in message
> news:ili9am$opp$1@news.eternal-september.org...
> > Michael Kennedy <mikek400@crap.comcast.net> wrote in message
> > news:waadnQx_0evQxebQnZ2dnUVZ_gqdnZ2d@giganews.com...
> >>
> >> "N_Cook" <diverse@tcp.co.uk> wrote in message
> >> news:ilfaie$3pr$1@news.eternal-september.org...
> >> > Michael Kennedy <mikek400@crap.comcast.net> wrote in message
> >> > news:VcydncYKZ9ShC-fQnZ2dnUVZ_q6dnZ2d@giganews.com...
> >> >> I have a Plasma tv that somehow I managed to partially tear one of
the

>
> I expected that I would be going back to Tokyo this weekend, but I am
> starting to think that I will be buying a plane ticket back home to
Florida.
>
> As far as I can see the situation went from out of control but possibly
> managable to now I would say inevitable major nuclear disaster with a very
> good chance of exposure where at my apartment just outside Tokyo.
>
> Thanks for looking into this.. Right now my concerns are on my friends in
> Tokyo who dont see the danger and arent leaving. They beleive what the
> government is saying that there is no danger. Many people couldnt believe
I
> was leaving Tokyo for safety and wont listen to my reasoning to leave.
>
>
>
>

Has it been reported in Japan whether the tsunami colder denser sea water
displaced the water in the storage ponds ?
Then what reaction occured with the sea water to end up combusting, and then
they started using sea water on the other reactors. Or did the pond/s crack
from the eaqrthquake and loose water?

==============================================================================
TOPIC: How to repair plastic seal for liquids used in human consumption?
http://groups.google.com/group/sci.electronics.repair/t/13de143057f9156c?hl=en
==============================================================================

== 1 of 2 ==
Date: Wed, Mar 16 2011 9:42 am
From: Robert Macy

Rich Webb, et al

Thank you for the emisupply URL! I ordered from them, they shipped
promptly, huge calking type tube of RTV like glue

Easy to work with, smells like vinegar, sticky and cured quickly [per
instruction/description]

Best of all! coffee pot does not leak and is now back in service!

HIGHLY RECOMMEND
EMI Supply
http://www.emisupply.com

Thanks again, I knew people here would know the answer

Robert

Rich Webb Apr 11 2010, 2:39 pm

From: Rich Webb <bbew...@mapson.nozirev.ten>
Date: Sun, 11 Apr 2010 17:39:55 -0400
Local: Sun, Apr 11 2010 2:39 pm
Subject: Re: How to repair plastic seal for liquids used in human
consumption?

On Sun, 11 Apr 2010 10:45:28 -0700 (PDT), Robert Macy
<m...@california.com> wrote:
>On Apr 11, 4:13 am, "William Sommerwerck" <grizzledgee...@comcast.net>
>wrote:
>> > What is the best way to reseal this junction, but preserve
>> > the requirement that the liquid in contact will be consumed
>> > by humans?

>> Silicone adhesives, as far as I know, are not particularly toxic in the
>> first place, and I doubt a properly cured bond would leach.

>> > Can food be placed in contact if I use superglue? Doubt it, but need
>> > confirmation.

>> Superglue isn't stable. It can be weakened simply by contact with water.

>> I'm inclined to agree with the poster who suggested buying a new pot.

>not an option

Short answer: GFGI

Medium answer: A search of "food grade adhesive" turns up some likely
candidates. This looks promising:
<http://www.emisupply.com/catalog/su5005-food-grade-silicone-
hitemp-10...>
--
Rich Webb Norfolk, VA

== 2 of 2 ==
Date: Wed, Mar 16 2011 12:11 pm
From: Rich Webb

On Wed, 16 Mar 2011 09:42:19 -0700 (PDT), Robert Macy
<macy@california.com> wrote:

>Rich Webb, et al
>
>Thank you for the emisupply URL! I ordered from them, they shipped
>promptly, huge calking type tube of RTV like glue
>
>Easy to work with, smells like vinegar, sticky and cured quickly [per
>instruction/description]
>
>Best of all! coffee pot does not leak and is now back in service!
>
>HIGHLY RECOMMEND
>EMI Supply
>http://www.emisupply.com
>
>Thanks again, I knew people here would know the answer

Glad it worked out!

Now that it's working, give <http://aerobie.com/products/aeropress.htm>
a try, though. Just got one recently and it's *wonderful* for the
occasional-cuppa-in-the-morning folks. Also quite fast to brew and an
easy clean-up.

--
Rich Webb Norfolk, VA

==============================================================================
TOPIC: motherboard RAM failures
http://groups.google.com/group/sci.electronics.repair/t/3e25b3ae78058770?hl=en
==============================================================================

== 1 of 3 ==
Date: Wed, Mar 16 2011 12:27 pm
From: Smitty Two

Recently starting building computers for a customer, using components
they supply, and have run into an alarming percentage (10?) of
motherboards that fail to recognize one RAM slot. Swapping the MB puts
them in order, and so far the customer has not had any problem returning
the bad MBs for credit to his vendor.

Is this a known epidemic? RoHS associated? I'm not being faulted for
this issue, but also wondering how likely it is that my (experienced)
employee is damaging the RAM slots when he plugs in the RAM.

All reasoned feedback appreciated.

== 2 of 3 ==
Date: Wed, Mar 16 2011 2:21 pm
From: Meat Plow

On Wed, 16 Mar 2011 12:27:42 -0700, Smitty Two wrote:

> Recently starting building computers for a customer, using components
> they supply, and have run into an alarming percentage (10?) of
> motherboards that fail to recognize one RAM slot. Swapping the MB puts
> them in order, and so far the customer has not had any problem returning
> the bad MBs for credit to his vendor.
>
> Is this a known epidemic? RoHS associated? I'm not being faulted for
> this issue, but also wondering how likely it is that my (experienced)
> employee is damaging the RAM slots when he plugs in the RAM.
>
> All reasoned feedback appreciated.

MB manufacturer?

--
Live Fast Die Young, Leave A Pretty Corpse

== 3 of 3 ==
Date: Wed, Mar 16 2011 3:32 pm
From: whit3rd

First cut, brush out the sockets (maybe it's just a bit of lint); second,
check the datasheet to be sure, sometimes the memory sizes and
socket numbers have to be in some specific order.

Third, return the board as defective, of course. A lot of manufacturers
put their boards through test with only one socket populated, and
that doesn't find all bad-socket issues. I even had one computer
that shut down every time socket #2 was used: the socket itself
was inserted backwards (it was shorting the whole power supply
through the memory module).

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