Solder and conductivity

[Suz]

The power lead on my laptop has broken again - I replaced it less than a year ago. It's a Dell laptop and the leads are notoriously flimsy around the bit where it plus into the laptop. The insulation has broken and the exposed wires have been pinging off one by one this last month.

I asked hubby would a drop of solder and loads of tape not sort it and he said he tried this last time but it didn't work.

My question is why does the solder not work? Is it conductivity of that type of solder? Is there an easy solution?

TIA Suzanne

[Rob Morley]

Solder only really provides an electrical connection - there should be something else providing mechanical strength to the joint. Presumably only the very end of the cable is exposed where it enters the plug, and this isn't enough area to make a good join. Also presumably Dell uses a proprietary connector so you can't just buy a new one and solder it on. To avoid the problem in future you could try applying a few layers of heatshrink tube to the plug/cable end so that stress is spread over a length of cable rather than all where it enters the plug.

[Andy Pandy]

Solder is intended to ' seal ' a good quality mechanical joint between two conductors. It has no physical strength and is not meant to carry current in that sense. Such faults where wires enter moulded plugs are non-repairable unless you are prepared to do a real bodge by cutting into the moulding ( Not recommended )

Andy

[dennis]

Does one of these fit?

?ModuleNo=42948&doy=5m10D?ModuleNo=42951&doy=5m10DThen you can solder it on the end of the lead.

[Grunff]

The only reason soldering wouldn't work is if your husband can't solder properly :-(

[PeTe33]

from my past experiences of trying to solder low voltage or thin stranded wires on flexible things (like speaker wires & stuff) what happens is..... you solder the wires without problem, but create a stiff un-flexible joint where solder ends and wires start.

Unless this point is adequately supported past the connection, after just a few wiggles of the wire it re-fractures losing connection.

Solder it's self is a good conductor.

[fred]

is the correct answer :-!

[The3rd Earl Of Derby]

Seems hubby has not been using flux based solder.

Give him a dig and tell him to do it right. :-)

-- Sir Benjamin Middlethwaite

[The3rd Earl Of Derby]

This is true, probably not heating the plug up long enough. Or the joint is not clean?

-- Sir Benjamin Middlethwaite

[The3rd Earl Of Derby]

[snip]

If the metal prong is dirty scrape the surface with a stanley blade. bare the wire and wrap solder around wire then heat the solder with soldering iron. Next get some solder flux paste from a local electronics shop, with the paste rub some on the plugs contacts till it flows into place then put some more paste on the contacts position wire/s over contacts and apply soldering iron till the solder melts then withdraw soldering iron but on no account move the soldered job otherwise dryness occurs.

And make sure the soldering iron is about 15 to 25Watts jobby. :-)

-- Sir Benjamin Middlethwaite

[Capitol]

It's still under guarantee on your information. Tell Dell(nicely) you want a new one, but reliable this time!!

Regards Capitol

[John Schmitt]

It is a small relief to know that I am not the only one who has bodged up an electrical connector. As for heatshrink, there is a variety available with hot-melt glue on the inside which is excellent for the job. Some years ago I was involved with resistivity measurements of terrain to locate stratum boundaries.This involved reels of wire which were about

500m long, which were attached to the base unit with "banana" plugs. The wires were forever being tripped over by students and that heatshrink meant that the wire did not rip out of the plug. Instead, I ended up straightening out the plugs.

John Schmitt

[The3rd Earl Of Derby]

I'd of thought this was an accident waiting to happen if students where tripping over wires in the work place.

-- Sir Benjamin Middlethwaite

[Suz]

When measuring stratum on rough terrain, it can hardly be described as "the work place"?

[mike ring]

"John Schmitt" wrote in news: [e-mail]:

This involved reels of wire

Gawd, if the reel's 500m long, how the hell much wire was on it.

You haven't got a name for this super heatshring, have you, sounds as thought I could use some

mike

[John Schmitt]

The manufacturer appears to be Tyco. Available in a diversity of starting diameters, precut lengths, or in rolls. A quick search on the RS website for "shrinkwrap adhesive lined" gave several pages of search results. Presumably the other players in the trade also supply it.

John Schmitt

[fred]

In article , John Schmitt writes

Adhesive lined heatshrink (tubing) is the generic term, I wouldn't use anything else these days as there is little that you use heatshrink for that does not benefit from some sort of strain relief, it also seals better than the much lauded self amalgamating tape.

[Ian White]

Better yet, repair the soldered connections, make sure they're good, and then flood the joint with hot-melt glue.

But even before you re-solder the wires, check whether the tubing is going to shrink down far enough to grip the cable. If the connector body is large and the cable is thin, you may need to build up the cable diameter with smaller heat-shrink or even PVC tape.

As others have said, do not rely on the thin wires or the solder for any mechanical strength at all. If you can, try to add some reinforcement before gluing, possibly using very small cable ties and plastic or wooden "splints".

Then follow-up with the adhesive-lined heatshrink tubing, which will partially melt the glue underneath and make a very strong bond.

That's about the best it can be bodged.

[mike ring]

Thanks, John and fred, must get some next time Matron lets me out

mike

[Suz]

Hubby has bodged it in some mysterious way that involves splints and loadsa tape. Won't tell me what's underneath because "you'll only tell that lot on uk-d-i-y" and went off muttering bad temperedly "wankers", "don't know how to solder indeed", and "get a life".

Hee hee hee. Much hilarity.

Suzanne