Trying to fix my keyless entry FOB for my car. SUPER TINY SOLDER

[Nifty]

My car's keyless entry FOB button stopped working so I called and the dealer wanted $180 for a new one and to program it!

I can get the units on eBay for $40, but I still have to pay the dealer $90 to program it (they are the only ones that can).

So I pulled it apart and found the tiny broken SMT switch. I ordered a replacement on eBay (10 for $3 free ship from China) and I'm going to try to de-solder the old one and re-solder on a new one. Oh, and yes, that's a dime for size reference.

I found this video on youtube VERY helpful: https://www.youtube.com/watch?v=3NN7UGWYmBY&playnext=1&list=PL684F581BDCDA2F04&feature=results_main



Wish me luck! If you have any advice, let me know!

 

[Nifty]

I do have a bit of soldering experience ( http://www.nifty-stuff.com/category/leds )... but nothing so tiny and delicately tight fitting as this!

 

[Boogity]

I have tried this with somewhat limited success.

Find a piece of #10 or #8 copper wire and strip the insulation off. Cut a 1" length of it and sharpen one end to a dull point. Use some fine steel or copper wire to strap this piece of wire to the side of your soldering iron tip. Make sure you have the piece of #10 tightly against the soldering tip. Heat the soldering iron. Dip the tip of the #10 into your flux - liquid flux works best for this but paste will do. Coat or "tin" the #10 with solder and go to work. This would not work very well with an electric soldering gun but it does much better with a pencil type or wood-burner type of soldering iron.

Good luck and please let us know how it works out for you.

 

[the funny farm6]

wow, good luck! i wouldnt be able to see well enough to do it.

 

[~gd]

If all else fails take it to a place that does Jewelry repair [not a place that just sells jewelry] or maybe an orthodontist. These are about the only people left that have experience in fine soldering. Frankly it looks like a piece of cake for one that can replace a prong holding a tiny diamond. Ask about the fee upfront! ~gd

 

[k15n1]

There's a 15-W soldering iron at radio shack that should do the trick.

You should be able to do this without too much trouble. Get some solder wick to take off the old part. Make sure you don't get it too hot for too long. The copper is glued down and it'll come off if you over-do it. If it's getting hot, let it cool off before going any further.

Once you have the old switch off, apply a little solder to ONE pad and set the switch in place. One it up until the solder reflows onto the switch. Oh, make sure the switch leads are tinned. Then it's stationary and you can solder down the other pads without a problem.

 

[Nifty]

Great advice, thanks all!

I have a solder wick and a cool solder removing vacuum plunger tool that works fantastically well for removing solder from stuff like this... so I'm hoping that won't be a problem.

I am worried that the switch may be attached to the PCB in some way other than the solder connections, but I doubt it.

I'm proceeding on the assumption that the switch orientation won't matter (aside from the direction of the leads).

Maybe I should pull some junk electronics apart and do some practicing in advance.

 

[Boogity]

Great advice, thanks all!

I have a solder wick and a cool solder removing vacuum plunger tool that works fantastically well for removing solder from stuff like this... so I'm hoping that won't be a problem. The vacuum de-soldering tools work very well. Just be careful with overheating the terminals.

I am worried that the switch may be attached to the PCB in some way other than the solder connections, but I doubt it. I doubt it,too.

I'm proceeding on the assumption that the switch orientation won't matter (aside from the direction of the leads). Look very carefully and you might find a tiny mark or notch somewhere that would help with orientation. Maybe on the side you can't see (yet).

Maybe I should pull some junk electronics apart and do some practicing in advance.

You'll do just fine.

 

[paradox]

Not sure what kind of vehicle you have but I recently bought a replacement key fob that had instructions on how to program it yourself. Took about 5 minutes. While I was shopping for mine I saw fobs for all kinds of cars that were the same way. Are you sure your car can only be done by the dealership?

 

[Nifty]

Ya, some cars you can do really cool button, radio, doorlock, open close combinations, etc. to program the units, but I'm not so lucky. For my car there is a way to do it without the dealer, but you have to remove a TON of stuff in the console to get at the things needed to do the reset. I'd actually prefer to buy from eBay and then pay the dealer $90 or whatever before taking all the console apart.