Hi
I have a nokia 3200 mobile whose power switch was detached. How can I
solder it back on?
Should I be using a soldering gun with a rosin core solder?

As you know the surfaces are too small and this in addition to the
intensive heat could destroy the board.

How can this be done the right way? Is there some sort of liquid solder
suitable for mini-components ?

"interuser" wrote in message
ups.com...
Hi
I have a nokia 3200 mobile whose power switch was detached. How can I
solder it back on?
Should I be using a soldering gun with a rosin core solder?

As you know the surfaces are too small and this in addition to the
intensive heat could destroy the board.

How can this be done the right way? Is there some sort of liquid solder
suitable for mini-components ?


You need a fine tipped iron, some fine solder and some SMT skills,
definitely NOT a soldering gun! If the switch is detached, are you sure it
didn't take the solder pads with it? That would make a straightforward
repair into a very tricky or even impractical one.

Dave

Dave D wrote:
"interuser" wrote in message
ups.com...
Hi
I have a nokia 3200 mobile whose power switch was detached. How can I
solder it back on?
Should I be using a soldering gun with a rosin core solder?

As you know the surfaces are too small and this in addition to the
intensive heat could destroy the board.

How can this be done the right way? Is there some sort of liquid solder
suitable for mini-components ?


You need a fine tipped iron, some fine solder and some SMT skills,
definitely NOT a soldering gun! If the switch is detached, are you sure it
didn't take the solder pads with it? That would make a straightforward
repair into a very tricky or even impractical one.

Dave

Can I have (pointers to) more instructions as to how to solder the
switch?
What are solder pads?
The contact points are silver if this helps.
I did manage to power on the mobile by connecting those points via a
wire

"interuser" wrote in message
oups.com...

Can I have (pointers to) more instructions as to how to solder the
switch?
What are solder pads?
The contact points are silver if this helps.

Solder pads = contact points. The fact they are still silver indicates they
are probably OK, so that's a good start.

I did manage to power on the mobile by connecting those points via a
wire


That's Good. You'll need a fine tipped soldering iron, preferably a
temperature controlled one but it's not essential. Use fine rosin cored
solder. Put the switch in place, and if possible get someone to hold it down
for you. When you are happy that the switch is located correctly, apply the
tip of the iron gently to one of the switch legs and solder pad. Quickly put
the solder onto the contact (not the iron!) and it should flow freely and
join the leg and the contact point. Repeat on each connection. Each one
should take a second of soldering time, any more and something is wrong-
either your iron is not hot enough, your technique is incorrect or the parts
to be soldered are tarnished/coated with something. If you keep the iron on
too long, the solder pad and possibly the switch will be destroyed and the
repair will be difficult to impossible.

While working on the phone, you must take antistatic precautions. Working on
an earthed metal kitchen sink will suffice if you don't have antistatic
wristbands etc.

Dave

On Fri, 9 Jun 2006 17:04:49 +0100, "Dave D"
opined:

"interuser" wrote in message
I did manage to power on the mobile by connecting those points via a
wire

That's Good. You'll need a fine tipped soldering iron, preferably a
temperature controlled one but it's not essential. Use fine rosin cored
solder. Put the switch in place, and if possible get someone to hold it down
for you.

A wooden clothes peg (possibly with the jaws whittled to a suitable
shape) is great for this.

When you are happy that the switch is located correctly, apply the
tip of the iron gently to one of the switch legs and solder pad. Quickly put
the solder onto the contact (not the iron!) and it should flow freely and
join the leg and the contact point. Repeat on each connection. Each one
should take a second of soldering time, any more and something is wrong-
either your iron is not hot enough, your technique is incorrect or the parts
to be soldered are tarnished/coated with something. If you keep the iron on
too long, the solder pad and possibly the switch will be destroyed and the
repair will be difficult to impossible.

nods

*Quickly* (1-2 seconds) tinning the switch legs & the PCB pads will
make the above quicker & easier. Let both parts cool for a short time
(30 seconds) before soldering them to each other.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Lionel wrote:
On Fri, 9 Jun 2006 17:04:49 +0100, "Dave D"
opined:

"interuser" wrote in message
I did manage to power on the mobile by connecting those points via a
wire

That's Good. You'll need a fine tipped soldering iron, preferably a
temperature controlled one but it's not essential. Use fine rosin cored
solder. Put the switch in place, and if possible get someone to hold it down
for you.

A wooden clothes peg (possibly with the jaws whittled to a suitable
shape) is great for this.

When you are happy that the switch is located correctly, apply the
tip of the iron gently to one of the switch legs and solder pad. Quickly put
the solder onto the contact (not the iron!) and it should flow freely and
join the leg and the contact point. Repeat on each connection. Each one
should take a second of soldering time, any more and something is wrong-
either your iron is not hot enough, your technique is incorrect or the parts
to be soldered are tarnished/coated with something. If you keep the iron on
too long, the solder pad and possibly the switch will be destroyed and the
repair will be difficult to impossible.

nods

*Quickly* (1-2 seconds) tinning the switch legs & the PCB pads will
make the above quicker & easier. Let both parts cool for a short time
(30 seconds) before soldering them to each other.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

I am not expert on using the soldering iron and I am afraid I may
damage the circuit.
Isn't there another way of doing this?
How about liquid solder or something else?

On 19 Jun 2006 22:35:57 -0700, "interuser"
opined:

Lionel wrote:
*Quickly* (1-2 seconds) tinning the switch legs & the PCB pads will
make the above quicker & easier. Let both parts cool for a short time
(30 seconds) before soldering them to each other.
[...]
I am not expert on using the soldering iron and I am afraid I may
damage the circuit.

That's a legitimate fear - it's very easy to damage a PCB if you're
inexperienced. My advice is to practice. If you can spare the
time/cash, go to a hobby electronics shop (Tandy/Radioshack, etc) &
buy a tiny piece of strip board or other prototyping PCB & practice
soldering small pieces of wire to the strips.

Isn't there another way of doing this?

The only sensible alternative would be to take the device to someone
with lots of soldering experience on small devices. If you take it to
any kind of repair shop, a half-hour of their standard labour charge
would be a fair price for a customer like yourself walking in off the
street. If it's a one man shop & you ask very politely, they may
charge you less. (If it were me, & you were someone I knew socially,
I'd probably charge you $20-30, depending on how messed up the damaged
area is, & turn it down if I didn't think it was fixable.)

How about liquid solder or something else?

Most of those sorts of things don't work make all that good an
electrical connection in the first place, & for a power switch, you'll
probably need a very good mechanical join as well, which you won't get
with any of the no-solder methods.

Sorry to sound like such a wet blanket, but I'd hate to give you
overly optimistic advice that'd most likely ruin your phone. Soldering
small parts safely requires practice, & if you can't find any way of
getting some practice, you should take it to an expert.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------

Lionel wrote in
:

On 19 Jun 2006 22:35:57 -0700, "interuser"
opined:

Lionel wrote:
*Quickly* (1-2 seconds) tinning the switch legs & the PCB pads will
make the above quicker & easier. Let both parts cool for a short time
(30 seconds) before soldering them to each other.
[...]
I am not expert on using the soldering iron and I am afraid I may
damage the circuit.

That's a legitimate fear - it's very easy to damage a PCB if you're
inexperienced. My advice is to practice. If you can spare the
time/cash, go to a hobby electronics shop (Tandy/Radioshack, etc) &
buy a tiny piece of strip board or other prototyping PCB & practice
soldering small pieces of wire to the strips.


Got any dead electronics? Practice on those. My advice is to try one of
the tasks I found hard: desoldering with a solder sucker bulb (Radio
shack, ~$5 US). If the joint isn't hot enough you won't get all the
solder. Too hot and you'll melt the board.

One more tip: Keep the tip clean. You can use a damp sponge or folded
paper towel to wipe off any collected gunk without unplugging the iron.

Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm