[Buerste]

I get a little bunch of laptop cast-offs for one reason or another. Often,
if they are current enough to be useful, I'll track down whatever parts they
need, within reason, and press them back into service with employees' kids
for school or such. Usually I get Dells and have great luck with parts and
well documented cures for their ailments. I even had one that required
resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with a
baseball bat. I've seen reports of resoldering this video card with a heat
gun at 750 degrees for a full three minutes. However, some of the people
reported melting off the components and blowing them away. At that point
you just scrap the whole machine. I'm thinking of making a jig to hold the
parts in place or try again with the tip extension. I can't afford to spend
any serious money on this but I hate to scrap the laptop just yet.

[Joe Pfeiffer]

"Buerste" writes:

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with a
baseball bat. I've seen reports of resoldering this video card with a heat
gun at 750 degrees for a full three minutes. However, some of the people
reported melting off the components and blowing them away. At that point
you just scrap the whole machine. I'm thinking of making a jig to hold the
parts in place or try again with the tip extension. I can't afford to spend
any serious money on this but I hate to scrap the laptop just yet.

Many people have reported success using a toaster oven as a reflow
oven...

[[email protected]]

On Mar 12, 7:40*pm, Joe Pfeiffer wrote:

Many people have reported success using a toaster oven as a reflow
oven...

That is true, Joe. But not with all the "hand add" parts on the board,
such as the connectors, etc.

Paul

[Jon Elson]

Buerste wrote:
I get a little bunch of laptop cast-offs for one reason or another. Often,
if they are current enough to be useful, I'll track down whatever parts they
need, within reason, and press them back into service with employees' kids
for school or such. Usually I get Dells and have great luck with parts and
well documented cures for their ailments. I even had one that required
resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with a
baseball bat. I've seen reports of resoldering this video card with a heat
gun at 750 degrees for a full three minutes. However, some of the people
reported melting off the components and blowing them away. At that point
you just scrap the whole machine. I'm thinking of making a jig to hold the
parts in place or try again with the tip extension. I can't afford to spend
any serious money on this but I hate to scrap the laptop just yet.


I do this sort of stuff all the time. Not fixing
laptops, but building and reworking stuff with our
own custom chips. Now, we are using a chip with
0.4 mm lead pitch, which is really getting to the
limits of what can be done by hand. I use a
stereo zoom microscope, and a couple Weller
soldering micro pencils. I use an EC1302B pencil
at home on an older soldering station, and a newer
WMP at work. For the micro stuff, they have a
pointed (conical) tip that is quite sharp.
Temperature usually 650 F for tin-lead solder, and
750 F for lead free. After getting too much
solder on there, I use the smallest desoldering
wick that I dip in GC liquid solder flux to make
it work better. I dip a foot or two at a time,
dry with a paper towel and let air dry for a
minute or two before using to desolder.

You really can't do this fine-pitch stuff without
some kind of magnifier, at least a head-mount
visor thing.

Jon

[Buerste]

"Calif Bill" wrote in message
m...

"Buerste" wrote in message
...
I get a little bunch of laptop cast-offs for one reason or another.
Often, if they are current enough to be useful, I'll track down whatever
parts they need, within reason, and press them back into service with
employees' kids for school or such. Usually I get Dells and have great
luck with parts and well documented cures for their ailments. I even had
one that required resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to
be from too much heat and too many thermal cycles cracking the joints on
the video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle
with a baseball bat. I've seen reports of resoldering this video card
with a heat gun at 750 degrees for a full three minutes. However, some
of the people reported melting off the components and blowing them away.
At that point you just scrap the whole machine. I'm thinking of making a
jig to hold the parts in place or try again with the tip extension. I
can't afford to spend any serious money on this but I hate to scrap the
laptop just yet.


Are these ball mount of lead chips? The ball mounts may not be able to be
redone without lots of equipment. The lead chips can be removed with a
desolder paste. Chip Quik http://www.chipquikinc.com/ is nice stuff.
As someone else says, the really fine pitch leads require a microscope.


I haven't extracted the card yet, work keeps getting in the way. I've
always wanted a good stereo boom microscope/camera...now I can justify it,
right?

[Calif Bill]

"Buerste" wrote in message
...
I get a little bunch of laptop cast-offs for one reason or another. Often,
if they are current enough to be useful, I'll track down whatever parts
they need, within reason, and press them back into service with employees'
kids for school or such. Usually I get Dells and have great luck with
parts and well documented cures for their ailments. I even had one that
required resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with
a baseball bat. I've seen reports of resoldering this video card with a
heat gun at 750 degrees for a full three minutes. However, some of the
people reported melting off the components and blowing them away. At that
point you just scrap the whole machine. I'm thinking of making a jig to
hold the parts in place or try again with the tip extension. I can't
afford to spend any serious money on this but I hate to scrap the laptop
just yet.


Are these ball mount of lead chips? The ball mounts may not be able to be
redone without lots of equipment. The lead chips can be removed with a
desolder paste. Chip Quik http://www.chipquikinc.com/ is nice stuff. As
someone else says, the really fine pitch leads require a microscope.

[K Ludger[_3_]]

"Buerste" wrote in message
...

"Calif Bill" wrote in message
m...

"Buerste" wrote in message
...
I get a little bunch of laptop cast-offs for one reason or another.
Often, if they are current enough to be useful, I'll track down whatever
parts they need, within reason, and press them back into service with
employees' kids for school or such. Usually I get Dells and have great
luck with parts and well documented cures for their ailments. I even had
one that required resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known
problematic video card. Replacement cards are not available. The
problem seems to be from too much heat and too many thermal cycles
cracking the joints on the video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle
with a baseball bat. I've seen reports of resoldering this video card
with a heat gun at 750 degrees for a full three minutes. However, some
of the people reported melting off the components and blowing them away.
At that point you just scrap the whole machine. I'm thinking of making
a jig to hold the parts in place or try again with the tip extension. I
can't afford to spend any serious money on this but I hate to scrap the
laptop just yet.


Are these ball mount of lead chips? The ball mounts may not be able to
be redone without lots of equipment. The lead chips can be removed with
a desolder paste. Chip Quik http://www.chipquikinc.com/ is nice stuff.
As someone else says, the really fine pitch leads require a microscope.


I haven't extracted the card yet, work keeps getting in the way. I've
always wanted a good stereo boom microscope/camera...now I can justify it,
right?


Try a very sharp small solder tip, resolder all the pins, dont worry about
shorts between pins. Then use solder wick to remove the excess solder. Use a
jewellers loupe (I've cut down a second loupe and mounted it on the back of
teh 1st one) with some solderwick and remove any excess solder and solder
bridges. You may need to clean excess flux between steps using isopropyl
alcohol or methylated spirits. This techinique regularly works for me - just
go slowly and carefully.

[Jim Wilkins]

On Mar 13, 2:37*am, "K Ludger" wrote:
"Buerste" wrote in message
"Calif Bill" wrote in message
om...

"Buerste" wrote in message
. ..
I get a little bunch of laptop cast-offs for one reason or another.

Try a very sharp small solder tip, resolder all the pins, dont worry about
shorts between pins. Then use solder wick to remove the excess solder. Use a
jewellers loupe (I've cut down a second loupe and mounted it on the back of
teh 1st one) with some solderwick and remove any excess solder and solder
bridges. You may need to clean excess flux between steps using isopropyl
alcohol or methylated spirits. This techinique regularly works for me - just
go slowly and carefully.-

Preferences vary a lot among techs depending on their experience,
vision and fine motor skills. For me an Optivisor with a #3, 14",
lens is right. I have the swing-away magnifier on the side of my
better eye to inspect but solder without it. You may find a microscope
difficult for a while because you lose depth perception, and the flux
fumes can condense on the lens unless you blow them away. Look for a
microscope with a long "working distance".

I need my wrist supported which rules out Panavise board holders, but
placing the board on the static mat is fine. I clamp small boards and
connectors in a 1-1/2" drill press vise.

Needle-pointed soldering iron tips don't work as well as slightly
larger conical tips for me. Power leads with a short path to internal
planes draw the heat away too quickly from fine cylindrical iron tips.
I usually have to bump the tip temperature up to 700F unless all the
pads connect to fine signal traces, then 650F is enough.

0.015" lead + rosin solder flows better than lead-free with no-clean
flux. The isopropyl alcohol I used for cleaning was semiconductor
grade. You can get 91% in drugstores.

If you are in a quiet area you can detect unsoldered leads by sliding
a needle probe across them and listening to the twang. An unsoldered
one sounds duller. You might have to try this on a known loose lead to
hear what I mean.

Jim Wilkins

[K Ludger[_3_]]

"Jim Wilkins" wrote in message
...
On Mar 13, 2:37 am, "K Ludger" wrote:
"Buerste" wrote in message
"Calif Bill" wrote in message
om...

"Buerste" wrote in message
. ..
I get a little bunch of laptop cast-offs for one reason or another.

Try a very sharp small solder tip, resolder all the pins, dont worry about
shorts between pins. Then use solder wick to remove the excess solder. Use
a
jewellers loupe (I've cut down a second loupe and mounted it on the back
of
teh 1st one) with some solderwick and remove any excess solder and solder
bridges. You may need to clean excess flux between steps using isopropyl
alcohol or methylated spirits. This techinique regularly works for me -
just
go slowly and carefully.-



SNIP


If you are in a quiet area you can detect unsoldered leads by sliding
a needle probe across them and listening to the twang. An unsoldered
one sounds duller. You might have to try this on a known loose lead to
hear what I mean.

Jim Wilkins


I puchased a "black head removal + splinter pick" tool from the pharmacy -
with a very fine point its good for finding the leads that are not stuck
down.

[Wild_Bill]

Many of the reliable techniques to repair solder faults have already been
mentioned.

A hot air iron is very effetive for small spot repairs without involving
nearby components. Hot air irons operate with no direct contact, so
transferring too much solder from a soldering iron tip to the device pins
doesn't become a problem.
Many times all that's needed besides heat is a very slight amount of
activated liquid rosin flux.
Using a toothpick to apply a tiny amount of the liquid flux is generally all
that's required.

A desoldering iron with a low air flow coming out of the tip may work as an
improvised hot air iron, but the air flow needs to be very limited volume or
the tip will get too cold to heat the air to desired temperatures.

FWIW, I have found one of the most useful tools is something that's often
thrown away. The round hardwood sticks that long cotton swabs are put on,
are very useful for examining and probing for loose pins. I cut the swab off
with flush cutting pliers at a low angle to the stick, making a useful sharp
tip.
These sticks are alo great for screw starters, by jamming a squared end into
a phillips recess, the stick holds surprisingly well. A tapered end will
work with smaller screws.

Flat hardwood sticks are great for burnishing and cleaning contacts. When
used with a deoxidizer solution, the round and flat sticks will clean
contacts very effectively without risk of scraping/scratching away thin
layers of plating.

With the ends squared off, flat sticks do a very good job for mixing small
amounts of epoxy and other compounds.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Buerste" wrote in message
...
I get a little bunch of laptop cast-offs for one reason or another. Often,
if they are current enough to be useful, I'll track down whatever parts
they need, within reason, and press them back into service with employees'
kids for school or such. Usually I get Dells and have great luck with
parts and well documented cures for their ailments. I even had one that
required resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with
a baseball bat. I've seen reports of resoldering this video card with a
heat gun at 750 degrees for a full three minutes. However, some of the
people reported melting off the components and blowing them away. At that
point you just scrap the whole machine. I'm thinking of making a jig to
hold the parts in place or try again with the tip extension. I can't
afford to spend any serious money on this but I hate to scrap the laptop
just yet.

[Jim Wilkins]

On Mar 13, 10:37*am, "Wild_Bill" wrote:
...
FWIW, I have found one of the most useful tools is something that's often
thrown away. The round hardwood sticks that long cotton swabs are put on,
are very useful for examining and probing for loose pins. ...
WB

You can also buy thicker, stiffer wooden sticks as "orange sticks", or
get shishkebab sticks in the grocery store.

Mash the end with pliers or a hammer to make a small flux brush, or
pull off some of the cotton.

An old toothbrush is about as good as anything for scrubbing flux
residue.

Tweezers fit better if you pull fine sandpaper through the closed tips
to cut them parallel.

[Jeff Wisnia]

Buerste wrote:
I get a little bunch of laptop cast-offs for one reason or another. Often,
if they are current enough to be useful, I'll track down whatever parts they
need, within reason, and press them back into service with employees' kids
for school or such. Usually I get Dells and have great luck with parts and
well documented cures for their ailments. I even had one that required
resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with a
baseball bat. I've seen reports of resoldering this video card with a heat
gun at 750 degrees for a full three minutes. However, some of the people
reported melting off the components and blowing them away. At that point
you just scrap the whole machine. I'm thinking of making a jig to hold the
parts in place or try again with the tip extension. I can't afford to spend
any serious money on this but I hate to scrap the laptop just yet.



Could tiny drops of conductive epoxy help in some of those cases?

It's sved my skin a few times.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

[Don Young]

"Buerste" wrote in message
...
I get a little bunch of laptop cast-offs for one reason or another. Often,
if they are current enough to be useful, I'll track down whatever parts
they need, within reason, and press them back into service with employees'
kids for school or such. Usually I get Dells and have great luck with
parts and well documented cures for their ailments. I even had one that
required resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with
a baseball bat. I've seen reports of resoldering this video card with a
heat gun at 750 degrees for a full three minutes. However, some of the
people reported melting off the components and blowing them away. At that
point you just scrap the whole machine. I'm thinking of making a jig to
hold the parts in place or try again with the tip extension. I can't
afford to spend any serious money on this but I hate to scrap the laptop
just yet.

The output of a heat gun can be custom tailored by fabricating nozzles,
baffles, and shields and by restricting the air intake and using a Variac to
control the temperature and speed of the blower. Soldering iron tips can be
custom made from copper to reach even around corners. With a custom baffle
on a heat gun, many chips can be fairly easily desoldered and replaced. I
was once fairly good at it but never did it enough to get really proficient
like some people are.

A good heat gun does work good to mass de-solder boards. Just heat carefully
till you see the solder melt and whack the board edge against something
solid. Nearly all the components will fall off cleanly unless they have
crimped leads.

Don Young

[Terry Coombs]

Jim Wilkins wrote:
On Mar 13, 10:37 am, "Wild_Bill" wrote:
...
FWIW, I have found one of the most useful tools is something that's
often thrown away. The round hardwood sticks that long cotton swabs
are put on, are very useful for examining and probing for loose
pins. ...
WB

You can also buy thicker, stiffer wooden sticks as "orange sticks", or
get shishkebab sticks in the grocery store.

Mash the end with pliers or a hammer to make a small flux brush, or
pull off some of the cotton.

An old toothbrush is about as good as anything for scrubbing flux
residue.

Tweezers fit better if you pull fine sandpaper through the closed tips
to cut them parallel.

Thec depth and breadth of knowledege in this place is astounding !!!
--
Snag
every answer
leads to another
question

[Buerste]

"Jeff Wisnia" wrote in message
eonecommunications...
Buerste wrote:
I get a little bunch of laptop cast-offs for one reason or another.
Often, if they are current enough to be useful, I'll track down whatever
parts they need, within reason, and press them back into service with
employees' kids for school or such. Usually I get Dells and have great
luck with parts and well documented cures for their ailments. I even had
one that required resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to
be from too much heat and too many thermal cycles cracking the joints on
the video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle
with a baseball bat. I've seen reports of resoldering this video card
with a heat gun at 750 degrees for a full three minutes. However, some
of the people reported melting off the components and blowing them away.
At that point you just scrap the whole machine. I'm thinking of making a
jig to hold the parts in place or try again with the tip extension. I
can't afford to spend any serious money on this but I hate to scrap the
laptop just yet.

Could tiny drops of conductive epoxy help in some of those cases?

It's sved my skin a few times.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Great minds think alike! I was wondering if I could use conductive paint
like window defroster repair kits.

[Jim Wilkins]

On Mar 13, 5:00*pm, Jeff Wisnia wrote:
...
Could tiny drops of conductive epoxy help in some of those cases?
It's sved my skin a few times.
Jeff

Silver epoxy is really nice stuff when you have rich Uncle to pay for
it (space project).

The shelf life is rather short, I kept it in a lab refrigerator and
still some of it went bad.

I used it to repair broken 1 mil x 5 mil gold wirebonds to salvage a
$40,000 laser diode chip. Don't ask me to try it again.

Jim Wilkins

[[email protected]]

On Thu, 12 Mar 2009 21:17:23 -0400, "Buerste" wrote:

I get a little bunch of laptop cast-offs for one reason or another. Often,
if they are current enough to be useful, I'll track down whatever parts they
need, within reason, and press them back into service with employees' kids
for school or such. Usually I get Dells and have great luck with parts and
well documented cures for their ailments. I even had one that required
resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with a
baseball bat. I've seen reports of resoldering this video card with a heat
gun at 750 degrees for a full three minutes. However, some of the people
reported melting off the components and blowing them away. At that point
you just scrap the whole machine. I'm thinking of making a jig to hold the
parts in place or try again with the tip extension. I can't afford to spend
any serious money on this but I hate to scrap the laptop just yet.


I had a butane powered soldering iron (Portosol, I think), that came
with several tips. One of these tips was a hot air tip. For heat
shrink tubing and the like. The hot air coming out was VERY hot but
the stream was quite small in diameter. Kind of hokey for heat
shrinking tubing because it would only heat a small spot at a time.
But if held too close to the tubing it would scorch the tubing. I
imagine that it might be perfect for surface mount spot reflow.
ERS

[DoN. Nichols]

On 2009-03-13, Jim Wilkins wrote:
On Mar 13, 2:37*am, "K Ludger" wrote:
"Buerste" wrote in message
"Calif Bill" wrote in message
om...

"Buerste" wrote in message
. ..
I get a little bunch of laptop cast-offs for one reason or another.

Try a very sharp small solder tip, resolder all the pins, dont worry about
shorts between pins. Then use solder wick to remove the excess solder. Use a
jewellers loupe (I've cut down a second loupe and mounted it on the back of
teh 1st one) with some solderwick and remove any excess solder and solder
bridges. You may need to clean excess flux between steps using isopropyl
alcohol or methylated spirits. This techinique regularly works for me - just
go slowly and carefully.-

Preferences vary a lot among techs depending on their experience,
vision and fine motor skills. For me an Optivisor with a #3, 14",
lens is right. I have the swing-away magnifier on the side of my
better eye to inspect but solder without it. You may find a microscope
difficult for a while because you lose depth perception,

That is where the stereo zoom microscopes win.

and the flux
fumes can condense on the lens unless you blow them away. Look for a
microscope with a long "working distance".

A Rotron muffin fan blowing across the soldering area helps
here.

I need my wrist supported which rules out Panavise board holders, but
placing the board on the static mat is fine. I clamp small boards and
connectors in a 1-1/2" drill press vise.

Hmm ... perhaps another Panavise with a soft wrist support held
along the bar?

Needle-pointed soldering iron tips don't work as well as slightly
larger conical tips for me. Power leads with a short path to internal
planes draw the heat away too quickly from fine cylindrical iron tips.
I usually have to bump the tip temperature up to 700F unless all the
pads connect to fine signal traces, then 650F is enough.

I've done work with a copper wire wound around the tip and then
extending as a fine tip. Not often, or I would have bought a tip which
was right for the task.

0.015" lead + rosin solder flows better than lead-free with no-clean
flux.

Absolutely. I bought several spools of the ultra-fine Pb/Sn
solder a few years ago at a hamfest, so I am now equipped with a
lifetime supply. :-)

The isopropyl alcohol I used for cleaning was semiconductor
grade. You can get 91% in drugstores.

Right -- though I have a much higher percentage two gallon
bottle saved for such work. (It is seldom opened, so it should still be
over 91%. :-)

If you are in a quiet area you can detect unsoldered leads by sliding
a needle probe across them and listening to the twang. An unsoldered
one sounds duller. You might have to try this on a known loose lead to
hear what I mean.

That one would almost certainly not work for me. I've got
terrible high frequency hearing, and have had it at least since
high-school days. (I was not tested before that, and had not realized
it on my own.)

Enjoy,
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 ---

[Wild_Bill]

I nearly always use lacquer thinner, Jim, for removing flux with cheap
cotton swabs which makes it almost effortless.

For tweezers and fine tipped pliers, filing the mis-matched jaw edges to
match them up helps improve the grip for things with very little protrusion,
like splinters.

FWIW, about a year ago I started using curly stainless steel kitchen/pot
scrubbers for cleaning soldering and desoldering iron tips, which works
great. It strips off flux and any oxidation with no damage to plated tips.
The scrubbers look like wads of thin SS lathe turnings. I poke a wad of it
into a small cup-like holder, and just jab the tip into the wad a couple of
times.

After years of using damp sponges, the scrubbers are much more effective.
Before sponges, I tried using steel wool, but quickly found out that was a
bad idea when I didn't notice I had transferred a piece of a fine strand
onto the circuit board, followed by a lot of confusion.
Braided tinned or bare copper shield from coaxial cable makes a decent tip
cleaner, too.

Another practice I got into the habit of is adding a little fresh solder to
tips right after turning the iron off. This has been working much better
than cleaning them very well before turning them off.
The result is a freshly tinned tip every time the iron is turned on for the
next use.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Jim Wilkins" wrote in message
...
On Mar 13, 10:37 am, "Wild_Bill" wrote:
...
FWIW, I have found one of the most useful tools is something that's often
thrown away. The round hardwood sticks that long cotton swabs are put on,
are very useful for examining and probing for loose pins. ...
WB

You can also buy thicker, stiffer wooden sticks as "orange sticks", or
get shishkebab sticks in the grocery store.

Mash the end with pliers or a hammer to make a small flux brush, or
pull off some of the cotton.

An old toothbrush is about as good as anything for scrubbing flux
residue.

Tweezers fit better if you pull fine sandpaper through the closed tips
to cut them parallel.

[Calif Bill]

wrote in message
...
On Thu, 12 Mar 2009 21:17:23 -0400, "Buerste" wrote:

I get a little bunch of laptop cast-offs for one reason or another.
Often,
if they are current enough to be useful, I'll track down whatever parts
they
need, within reason, and press them back into service with employees' kids
for school or such. Usually I get Dells and have great luck with parts
and
well documented cures for their ailments. I even had one that required
resoldering a surface-mounted chip with solder cracks.

The current one is a Toshiba Satellite 5105-S501 with a known problematic
video card. Replacement cards are not available. The problem seems to be
from too much heat and too many thermal cycles cracking the joints on the
video memory chips.

On the Dell, I made an extension for a pencil soldering iron from 28 ga
wire. It worked after three tries but it was like threading a needle with
a
baseball bat. I've seen reports of resoldering this video card with a
heat
gun at 750 degrees for a full three minutes. However, some of the people
reported melting off the components and blowing them away. At that point
you just scrap the whole machine. I'm thinking of making a jig to hold
the
parts in place or try again with the tip extension. I can't afford to
spend
any serious money on this but I hate to scrap the laptop just yet.


I had a butane powered soldering iron (Portosol, I think), that came
with several tips. One of these tips was a hot air tip. For heat
shrink tubing and the like. The hot air coming out was VERY hot but
the stream was quite small in diameter. Kind of hokey for heat
shrinking tubing because it would only heat a small spot at a time.
But if held too close to the tubing it would scorch the tubing. I
imagine that it might be perfect for surface mount spot reflow.
ERS

There are adapters for different type packages for hot air guns. Look at
Digikey.com and do a search on soldering.

[Jim Wilkins]

On Mar 14, 8:49*pm, "DoN. Nichols" wrote:
On 2009-03-13, Jim Wilkins wrote:

You may find a microscope
difficult for a while because you lose depth perception,

* * * * That is where the stereo zoom microscopes win.

I mentioned it because used microscopes can be expensive and you may
not be able to try working under one before buying it. Mine has 100mm
of clearance below the head.