Need a small parts soldering iron

[atgcpaul]

Our GPS can be powered by AA batteries or through a cigarette lighter that
connects to the mini USB connector on the GPS. The mini connector snapped
off. The 4 soldered connections are very small and close to each other. I'm not
the most adept solderer. Any one have recommendations for a soldering iron I
can use to get to these small connections? Do they make a liquid soldering
pen that dries hard? I used a pencil type soldering iron like 10 years ago. OK
for what I needed but the tip was gargantuan. ColdHeat seemed appropriate
for this but have read too many bad reviews.

The connector was originally glued to the board. I don't think those tiny
soldering joints were holding it in place. I have reglued it but I suppose there's
still an open circuit because it still isn't working. Batteries do work but don't
want to keep that up. I've lost count of the number of times we lost power
<5 miles from our destination.

Thanks, Paul

[LCHIEN]

most of that stuff need special soldering equipment. Cold heat, forget that.
Virtually all high production quantity consumer products are now based upon surface mount (vs. thru hole) components now with connector pitches down to .03" or less.
You need a very fine electronics soldering iron, not the kind you get at radio shack anymore, to do this IF YOU CAN EVEN REACH the connections. In many cases, you need special solder paste applied to pads on the board and blow a very fine stream of hot air under the part to melt the solder to the leads. This assumes all pins are pristine and coplanar within about .005 "

Unless you are really good at this kind of assembly and have the correct tools, its a factory repair.

Make sure in the future that you don't jerk on the power cable. They're small and tiny but not that robust.

[Uncle Cracker]

Cold Heat sucks! There are still a few retail-type irons out there that have a fine, conical tip. One like that, along with a rigid-mounted magnifying glass, may allow you to do what you are needing done. Try to find some rosin-core solder with lead, if you can. Try to get in and out with the iron as quickly as you can for each connection. And Loring is correct, many of those miniaturized surface-mount components so much in use nowadays are impossible to work with unless you have the proper production-type equipment.

[jziegler]

Loring is right on this one. The cheapest soldering station to handle something like you need start at around $100. You need a very fine tip and temperature control.

An easier "fix" might be a cable the connects into the battery compartment and goes to the lighter plug in the car (you'd need to step down the voltage for this to work). A universal type lighter plug set to the right voltage and clipped or soldered to the terminals in the battery compartment would be much easier to solder.

Of course, if you get up to the Wilmington DE area, it's possible that I could help.

Jim

[TheRic]

Not sure if this will work in your case but I have repaired several circuit boards with this, normally redrawing circuit lines.

Go to your local auto parts store. They will have a repair kit for your rear defogger (wires in / on back window). Here is one brand ...

http://www.amazon.com/Permatex-15067.../dp/B000HBI9YQ

It's a liquid that will conduct electric when it dries. It comes in a bottle with a small brush think nail polish (it's about that thickness also). You can use either that brush or use just 1 bristol / hair to put a drop (or several) on the connections.

[atgcpaul]

Not sure if this will work in your case but I have repaired several circuit boards with this, normally redrawing circuit lines.

Go to your local auto parts store. They will have a repair kit for your rear defogger (wires in / on back window). Here is one brand ...

Very cool, Ric. I just bought some at Advanced AutoParts. Thanks for the
heads up. I'll give it a try tonight using a pin or toothpick to apply it.


Thanks, Paul

[Daryl]

When I need a fine tip I wrap a couple turns of 12 or 14g copper wire around the tip, shape it with a file and tin it. It will usually hold more than enough solder to make a couple small connections.

[atgcpaul]

Not sure if this will work in your case but I have repaired several circuit boards with this, normally redrawing circuit lines.

Go to your local auto parts store. They will have a repair kit for your rear defogger (wires in / on back window). Here is one brand ...

SUCCESS!!! My first attempt was partially successful. A little too much of this
special solder caused the GPS to flip out a little. I took it apart again, scraped
off some excess, and now it's as good as new. I only fixed the 2 connections
that supply power and ground. Couldn't be more pleased with myself right now.

Thanks Ric and the rest for your suggestions.

Paul

[JSUPreston]

Just for everyone's reference, I have a Cold Heat. Waste of $20. Only thing useful out of the kit is the solder, which I've been using with my HF soldering irons I got over 10 years ago.