Hi all,

I have done some soldering on my gameboy advance and have created a dry
joint, I would like to know if is possible to test a solder joint using
a multimeter if so how and what make is recommended (I don't need
anything fancy).

Thanks
Grant

"Grant" wrote in message
ups.com...
Hi all,

I have done some soldering on my gameboy advance and have created a dry
joint, I would like to know if is possible to test a solder joint using
a multimeter if so how and what make is recommended (I don't need
anything fancy).

Thanks
Grant


Just look at it, if it's dry it'll look dull. Don't use lead-free solder if
you can help it, that stuff is crap, even after years of soldering I still
can't make a nice joint with it.

"James Sweet" bravely wrote to "All" (26 Oct 04 05:20:19)
--- on the heady topic of " Testing solder joint"

JS From: "James Sweet"

JS "Grant" wrote in message
JS ups.com...
Hi all,

I have done some soldering on my gameboy advance and have created a dry
joint, I would like to know if is possible to test a solder joint using
a multimeter if so how and what make is recommended (I don't need
anything fancy).

Thanks
Grant


JS Just look at it, if it's dry it'll look dull. Don't use lead-free
JS solder if you can help it, that stuff is crap, even after years of
JS soldering I still can't make a nice joint with it.

It is possible to test the resistivity of the joint using a milli-ohm
meter. It's may be a hard to find gadget though so one could
alternately inject 1 ampere of current and measure the voltage drop
using the 200mV scale of a dmm. i.e. a 7mV reading equals 7milli-ohms.

The acceptable resistivity of the joint would depend on the amount of
expected current. Generally speaking anything below 50 milli-ohms
would be okay. However, for large currents I'd want less than 10
milli-ohms. i.e. 10 amperes at 10 milli-ohms is 100 milli watt.
An ideal 1 milli-ohm or less might not be easily achieved. However if
the component lead is bent flat over the conductive trace it may be
much closer to zero ohms than if left floating in solder as is common.

A*s*i*m*o*v

.... Power is obtained by current meeting resistance

We all know it when we see it. It's got a fairly characteristic look to it
but ...

A) What, physically, is a cold solder joint?


and

B) What are the electrical characteristics of a cold solder joint?

TIA

Norm

"Norm Dresner" wrote in message
...
|
| We all know it when we see it. It's got a fairly characteristic look to
it
| but ...
|
| A) What, physically, is a cold solder joint?

It is an unwetted connection between solder and other metals. Think blobs of
water on a greasy pan.


| and
|
| B) What are the electrical characteristics of a cold solder joint?

Variable. Sometimes they work for 10 years then fail. Usually they make
intermittent connection. Sometimes they make no connection at all without
external pressure.

N

"NSM" wrote in message news:AFCgd.39769$9b.12504@edtnps84...
"Norm Dresner" wrote in message
...
|
| We all know it when we see it. It's got a fairly characteristic look to
it
| but ...
|
| A) What, physically, is a cold solder joint?

It is an unwetted connection between solder and other metals. Think blobs of
water on a greasy pan.


| and
|
| B) What are the electrical characteristics of a cold solder joint?

Variable. Sometimes they work for 10 years then fail. Usually they make
intermittent connection. Sometimes they make no connection at all without
external pressure.

N

A cold solder joint is when the part being soldered was not heated
enough for the solder to grab on to it properly.

On Fri, 29 Oct 2004 22:29:37 GMT, "Norm Dresner"
wrote:


We all know it when we see it. It's got a fairly characteristic look to it
but ...

A) What, physically, is a cold solder joint?


If I remember correctly, a good solder joint should create an actual
chemical/physical change/bond at the surfaces of the lead and the
solder pad. The metals actually join chemically. A cold solder joint
likely would not accomplish this. Just a guess, sort of an educated
one, maybe.

Tom


and

B) What are the electrical characteristics of a cold solder joint?

TIA

Norm

"Grant" wrote in message
ups.com...
Hi all,

I have done some soldering on my gameboy advance and have created a dry
joint, I would like to know if is possible to test a solder joint using
a multimeter if so how and what make is recommended (I don't need
anything fancy).

A dry, grainy looking blob is not good. Add some good flux and reheat it
.... usually works fine.

Thanks for the advice guys

Grant