Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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jim rozen
 
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In article , Jeff Wisnia says...

Robert Swinney wrote:
So Jim, what are the electronics for? I sorta figured the new LEDs used
(only) appropriate dropping resistors like older conventional LEDs.


Likely it's a dc to dc converter of some sort, much more efficient than
wasting power in a dropping resistor. I'm amazed at the kind of
efficiencies I see claimed in chip manufacturer's ads these days.

Jim just confirmed what I've been saying for the last ten years or so,
repair of consumer electronics has become more of a mechanical job than
an electronic troubleshooting one. The parts themselves hardly ever fail
these days, it's mainly "loose disconnections" that keep the parts from
doing their intended tasks.


The electronics are two transistors, a couple of resistors, and a
flyback inductor, to boost the voltage so that a white LED that takes
four volts to turn on, can be run off of two AAA batteries that only
make three volts.

Now if I only could have found the loose connection that made my
daughter's cell phone stop working - not that I didn't inspect
every bit of the board under a microscope for an hour or so!

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
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  #2   Report Post  
Jeff Wisnia
 
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jim rozen wrote:

In article , Jeff Wisnia says...

Robert Swinney wrote:

So Jim, what are the electronics for? I sorta figured the new LEDs used
(only) appropriate dropping resistors like older conventional LEDs.



Likely it's a dc to dc converter of some sort, much more efficient than
wasting power in a dropping resistor. I'm amazed at the kind of
efficiencies I see claimed in chip manufacturer's ads these days.

Jim just confirmed what I've been saying for the last ten years or so,
repair of consumer electronics has become more of a mechanical job than
an electronic troubleshooting one. The parts themselves hardly ever fail
these days, it's mainly "loose disconnections" that keep the parts from
doing their intended tasks.



The electronics are two transistors, a couple of resistors, and a
flyback inductor, to boost the voltage so that a white LED that takes
four volts to turn on, can be run off of two AAA batteries that only
make three volts.

Now if I only could have found the loose connection that made my
daughter's cell phone stop working - not that I didn't inspect
every bit of the board under a microscope for an hour or so!

Jim



Deja vu all over again Jim. My youngest (17 year old) son sat on or
whacked the stuubby little antenna on his two month old Motorola camera
phone (which I'd just bought him to replace the previous phone which he
lost somewhere.) and it twisted over in the plastic threads of the
housing so that it's inside end scrubbed several tiny surface mount
parts right off the board.

Because our cellphone carrier (Cingular) is no longer doing any service
work on phones at their stores here in Taxachusetts, sick phones have to
be mailed in for repair, so I figured there was no chance I could FTF
sweet talk a local repair guy into doing me a favor and fixing it on the
sly. The mail-in service operation wanted $150 to exchange a "damaged"
phone. (Yeah, I know, I should have sprung for the "all risk" insurance
Cingular wanted to sell me, but I must have been projecting my cautious
experience and not thinking about the kid's, so I declined it.)

I couldn't Google up anything in the way of a print for the phone, and I
figured I'd go nuts trying to reverse engineer it and then obtain the
components it needed, so I just pulled the SIM card out of it, chucked
the phone in the trash, and bought the kid a rugged, non-flip, internal
antenna ex-Cingular Nokia complete with wall and car chargers for $30 on
eBay.

Stuck the SIM card into it, made a quick phone call to Conversent so
they could plug the phone's ID numbers into their computer, and he was
on the air again. He can bloody well live with a plebian phone until
he's on his own - Ha!

(It's times like this when I think children are G-d's punishment for
having sex.)

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"As long as there are final exams, there will be prayer in public
schools"
  #3   Report Post  
Gunner
 
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On Mon, 06 Dec 2004 13:02:53 -0500, Jeff Wisnia
wrote:


I couldn't Google up anything in the way of a print for the phone, and I
figured I'd go nuts trying to reverse engineer it and then obtain the
components it needed, so I just pulled the SIM card out of it, chucked
the phone in the trash, and bought the kid a rugged, non-flip, internal
antenna ex-Cingular Nokia complete with wall and car chargers for $30 on
eBay.

Stuck the SIM card into it, made a quick phone call to Conversent so
they could plug the phone's ID numbers into their computer, and he was
on the air again. He can bloody well live with a plebian phone until
he's on his own - Ha!

(It's times like this when I think children are G-d's punishment for
having sex.)

Jef


You had some doubts??????

Gunner

"To be civilized is to restrain the ability to commit mayhem.
To be incapable of committing mayhem is not the mark of the civilized,
merely the domesticated." - Trefor Thomas
  #4   Report Post  
Robert Swinney
 
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Yep! Like Jeff said, some sort of a DC to DC thingie. Comments regarding
mechanical repair to modern electronics reminds me: RCA Colortrack TV
receiver - mid '80s model. Modularized; a problem tracked down to the tuner
control module - opened up tuner control module and found a note under the
shield that the "new" set had already been serviced before it was sold to
me. The pecker tracks therein must have been the first fix for an
"intermittent" in the module because it came clear (again) when I
reinstalled it.

Some time later, when the problem reappeared I was able to fix it with a
popsicle stick propped under the rear of the tuner control module. Now this
was "really cool" - complex electronic problem fixed with a popsicle stick!

Over the years, the module would exhibit the same problem which was handily
repaired via the popsicle stick fix. Ultimately, a stack of popsicle sticks
failed to clear the problem - like it was still intermittent, over a cycle
of months, or sometimes years.

Optovisor (finally) to the rescue revealed a tiny PCB crack around an edge
card connector on the front of the module. This was 4 or 5 years ago.
After soldering over the crack, the old RCA has given trouble-free service
as a bedroom set ever since.

Bob Swinney



"jim rozen" wrote in message
...
In article , Jeff Wisnia says...

Robert Swinney wrote:
So Jim, what are the electronics for? I sorta figured the new LEDs used
(only) appropriate dropping resistors like older conventional LEDs.


Likely it's a dc to dc converter of some sort, much more efficient than
wasting power in a dropping resistor. I'm amazed at the kind of
efficiencies I see claimed in chip manufacturer's ads these days.

Jim just confirmed what I've been saying for the last ten years or so,
repair of consumer electronics has become more of a mechanical job than
an electronic troubleshooting one. The parts themselves hardly ever fail
these days, it's mainly "loose disconnections" that keep the parts from
doing their intended tasks.


The electronics are two transistors, a couple of resistors, and a
flyback inductor, to boost the voltage so that a white LED that takes
four volts to turn on, can be run off of two AAA batteries that only
make three volts.

Now if I only could have found the loose connection that made my
daughter's cell phone stop working - not that I didn't inspect
every bit of the board under a microscope for an hour or so!

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================



  #5   Report Post  
Martin H. Eastburn
 
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Jim -
know the direction of hit - then look at the massive object - how the gravity
does stuff. Might be a break in the pcb due to a pull...
Mechanical fit that isn't mated directly...

Martin

jim rozen wrote:

In article , Jeff Wisnia says...

Robert Swinney wrote:

So Jim, what are the electronics for? I sorta figured the new LEDs used
(only) appropriate dropping resistors like older conventional LEDs.



Likely it's a dc to dc converter of some sort, much more efficient than
wasting power in a dropping resistor. I'm amazed at the kind of
efficiencies I see claimed in chip manufacturer's ads these days.

Jim just confirmed what I've been saying for the last ten years or so,
repair of consumer electronics has become more of a mechanical job than
an electronic troubleshooting one. The parts themselves hardly ever fail
these days, it's mainly "loose disconnections" that keep the parts from
doing their intended tasks.



The electronics are two transistors, a couple of resistors, and a
flyback inductor, to boost the voltage so that a white LED that takes
four volts to turn on, can be run off of two AAA batteries that only
make three volts.

Now if I only could have found the loose connection that made my
daughter's cell phone stop working - not that I didn't inspect
every bit of the board under a microscope for an hour or so!

Jim




--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder


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jim rozen
 
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In article , Martin H.
Eastburn says...

Jim -
know the direction of hit - then look at the massive object - how the gravity
does stuff. Might be a break in the pcb due to a pull...
Mechanical fit that isn't mated directly...

Martin


Ah, it's a moot point now.

Last night I mentioned to my wife that I had fixed the flashlight.

"Oh, what went wrong with it?"

"Some of the parts had come off the circuit board, and I
was eminently clever and managed to fix it. Damn I'm smart."

Or some other kind of preening to that effect.

I proceeded to unscrew the lens to show her what a great
microelectronics handyman I really am.

The lens flipped out of my fingers as it screwed off the
barrel of the light, and flipped across the room. Because
I tracked it closely as it spun across the floor, I found
it right away under the kitchen table.

The circuit board, with LED attached, had come loose and
flew off in some other direction.

Correction: some other *dimension*. It's gone now, I can
say that for sure after seaching for an hour. After looking
high and low, I finally decided that it must have dropped down
into the hole in the kitchen floor where there had been an
old heating pipe at one time.

So I went down the basement and peered up onto the top of the
beam that was right under the hole. Yep, there was something
there. With the aid of an inspection mirror and a (different)
flashlight I extracted the object.

Dumbfounded, I held an adapter that I had made years ago, to
fit PR-style flashlight bulbs into antique navy battle lanterns,
which take DC bayonette lamps. I'm sure I must have looked
for *that* thing for a few hours, ten years ago.

Maybe in ten years I'll be looking for something else and
find that LED on its board. In the meantime I think
I'll plug that damn hole up.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================
  #7   Report Post  
Harold & Susan Vordos
 
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"jim rozen" wrote in message
...
In article , Martin H.
Eastburn says...

Jim -
know the direction of hit - then look at the massive object - how the

gravity
does stuff. Might be a break in the pcb due to a pull...
Mechanical fit that isn't mated directly...

Martin


Ah, it's a moot point now.

Last night I mentioned to my wife that I had fixed the flashlight.

"Oh, what went wrong with it?"

"Some of the parts had come off the circuit board, and I
was eminently clever and managed to fix it. Damn I'm smart."

Or some other kind of preening to that effect.

I proceeded to unscrew the lens to show her what a great
microelectronics handyman I really am.

The lens flipped out of my fingers as it screwed off the
barrel of the light, and flipped across the room. Because
I tracked it closely as it spun across the floor, I found
it right away under the kitchen table.

The circuit board, with LED attached, had come loose and
flew off in some other direction.

Correction: some other *dimension*. It's gone now, I can
say that for sure after seaching for an hour. After looking
high and low, I finally decided that it must have dropped down
into the hole in the kitchen floor where there had been an
old heating pipe at one time.

So I went down the basement and peered up onto the top of the
beam that was right under the hole. Yep, there was something
there. With the aid of an inspection mirror and a (different)
flashlight I extracted the object.

Dumbfounded, I held an adapter that I had made years ago, to
fit PR-style flashlight bulbs into antique navy battle lanterns,
which take DC bayonette lamps. I'm sure I must have looked
for *that* thing for a few hours, ten years ago.

Maybe in ten years I'll be looking for something else and
find that LED on its board. In the meantime I think
I'll plug that damn hole up.

Jim



I was told to expect days like that, but no one warned me that they'd all be
that way!

Harold


  #8   Report Post  
Ken Sterling
 
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In article , Martin H.
Eastburn says...

Jim -
know the direction of hit - then look at the massive object - how the gravity
does stuff. Might be a break in the pcb due to a pull...
Mechanical fit that isn't mated directly...

Martin


Ah, it's a moot point now.

Last night I mentioned to my wife that I had fixed the flashlight.

"Oh, what went wrong with it?"

"Some of the parts had come off the circuit board, and I
was eminently clever and managed to fix it. Damn I'm smart."

Or some other kind of preening to that effect.

I proceeded to unscrew the lens to show her what a great
microelectronics handyman I really am.

The lens flipped out of my fingers as it screwed off the
barrel of the light, and flipped across the room. Because
I tracked it closely as it spun across the floor, I found
it right away under the kitchen table.

The circuit board, with LED attached, had come loose and
flew off in some other direction.

Correction: some other *dimension*. It's gone now, I can
say that for sure after seaching for an hour. After looking
high and low, I finally decided that it must have dropped down
into the hole in the kitchen floor where there had been an
old heating pipe at one time.

So I went down the basement and peered up onto the top of the
beam that was right under the hole. Yep, there was something
there. With the aid of an inspection mirror and a (different)
flashlight I extracted the object.

Dumbfounded, I held an adapter that I had made years ago, to
fit PR-style flashlight bulbs into antique navy battle lanterns,
which take DC bayonette lamps. I'm sure I must have looked
for *that* thing for a few hours, ten years ago.

Maybe in ten years I'll be looking for something else and
find that LED on its board. In the meantime I think
I'll plug that damn hole up.

Jim


--
================================================= =
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
================================================= =

Teehee.... I've spent 1/2 my life (so far) crawling around looking for
"lost" items. Some found, some not. Was working on a 76 Chevy pickup
of mine one time, rebuilding carb - disconnected the two throttle
return springs (one inside the other) = *never* did find them. sigh.
Ken.

  #9   Report Post  
Gunner
 
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On Tue, 07 Dec 2004 22:27:43 GMT, Ken Sterling (Ken Sterling) wrote:

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

Teehee.... I've spent 1/2 my life (so far) crawling around looking for
"lost" items. Some found, some not. Was working on a 76 Chevy pickup
of mine one time, rebuilding carb - disconnected the two throttle
return springs (one inside the other) = *never* did find them. sigh.
Ken.




"As physicists now know, there is some nonzero probability
that any object will, through quantum effects, tunnel from the
workbench in your shop to Floyds Knobs, Indiana (unless your
shop is already in Indiana, in which case the object will tunnel
to Trotters, North Dakota). The smaller mass of the object, the
higher the probability. Therefore, disassembled parts,
particularly small ones, of machines disappear much faster than
assembled machines." Greg Dermer: rec.crafts.metalworking
  #10   Report Post  
jim rozen
 
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In article , Gunner says...

"As physicists now know, there is some nonzero probability
that any object will, through quantum effects, tunnel from the
workbench in your shop to Floyds Knobs, Indiana (unless your
shop is already in Indiana, in which case the object will tunnel
to Trotters, North Dakota). The smaller mass of the object, the
higher the probability. Therefore, disassembled parts,
particularly small ones, of machines disappear much faster than
assembled machines." Greg Dermer: rec.crafts.metalworking


Yep. That's exactly what happened. If any of you kind folk
happen to find my LED flashlight innards, please give a holler.

Thank you.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================


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DoN. Nichols
 
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In article ,
jim rozen wrote:
In article , Gunner says...

"As physicists now know, there is some nonzero probability
that any object will, through quantum effects, tunnel from the
workbench in your shop to Floyds Knobs, Indiana (unless your
shop is already in Indiana, in which case the object will tunnel
to Trotters, North Dakota). The smaller mass of the object, the
higher the probability. Therefore, disassembled parts,
particularly small ones, of machines disappear much faster than
assembled machines." Greg Dermer: rec.crafts.metalworking


Yep. That's exactly what happened. If any of you kind folk
happen to find my LED flashlight innards, please give a holler.


Glad to -- if you will only post a link to an image of the
innards, so we know what they look like. :-)

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
  #12   Report Post  
Peter W. Meek
 
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On 7 Dec 2004 05:09:38 -0800, jim rozen
wrote:

The lens flipped out of my fingers as it screwed off the
barrel of the light, and flipped across the room. Because
I tracked it closely as it spun across the floor, I found
it right away under the kitchen table.

The circuit board, with LED attached, had come loose and
flew off in some other direction.


A LONG time ago (as will be seen) I dropped a small,
irreplaceable part. As all fumble-fingers must do,
I had trained myself to freeze and listen carefully
at the first hint of dropping something: dead silence.
I looked everywhere that might have muffled the sound
of a small part landing and rolling away, but couldn't
find it. Later, I found the part in my pant cuff. (When
was the last time you wore trousers with permanent cuffs?
For me it must have been late '50s or early '60s.)

Correction: some other *dimension*. It's gone now, I can
say that for sure after seaching for an hour. After looking
high and low, I finally decided that it must have dropped down
into the hole in the kitchen floor where there had been an
old heating pipe at one time.

So I went down the basement and peered up onto the top of the
beam that was right under the hole. Yep, there was something
there. With the aid of an inspection mirror and a (different)
flashlight I extracted the object.

Dumbfounded, I held an adapter that I had made years ago, to
fit PR-style flashlight bulbs into antique navy battle lanterns,
which take DC bayonette lamps. I'm sure I must have looked
for *that* thing for a few hours, ten years ago.

Maybe in ten years I'll be looking for something else and
find that LED on its board. In the meantime I think
I'll plug that damn hole up.


Don't do that; you will never have the impetus of losing
something else down the hole to cause you to find the LED.

--
--Pete
"Peter W. Meek"
http://www.msen.com/~pwmeek/
  #13   Report Post  
Harold & Susan Vordos
 
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"Peter W. Meek" wrote in message
...
snip----]

(When
was the last time you wore trousers with permanent cuffs?
For me it must have been late '50s or early '60s.)


Ha! I don't recall when that was. The first thing I did with work pants
in "the good old days" was to remove the cuff. Those suckers can hold one
hell of a lot of chips, not just irreplaceable parts!

H


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