Help with some 'micro' soldering anyone?

Auscast

Hello!
I'm looking for a little help and hope someone here will be able to help me.
So, story is, the wife and I just bought a 00 Renault Clio and it's a great little car for the price, only problem is that the central locking (typically) stopped working a few days after we got it.
On closer inspection I have discovered the micro switch on the little motherboard inside the key has broken off at the solder points. I have a pretty good photo of what's happened here:

I had it sorted for about a day with some aluminum foil and sticky tape, but it's not the best option.

So instead of me waiting 2 and a half weeks and paying through the nose for a new key, I thought someone with the right tools might be able to solder the switch back on for me for a pint or 2. I live in Dundrum and am able to get around the city if needed.

Cheers, Simon.

Solitaire

Moved to Motors, think you'll be needing a new keyfob Same happened to me with my Focus

Even if you could solder it you'd have to replace the switch, as judging from the pic the metal contact appears to have broken off inside the microswitch housing. Also had this issue myself...

paddy

Hi Simon, what length is the broken switch?

corglass

hey Simon,

Just to let you know (I case you havn't thought of it)

ANY switch will work here, you could get on off a doner fob? or someone here on Boards might be kind enough to send you their old one to rob the switch from.......

squod

Single pole single throw momentary switch, push to make. Radionics have a telephone number for tech support.
Somewhere over here; http://radionics.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&binCount=1216&Ne=4294957972&N=4294964201+4294957718

Or call into peats, parts department. They used to have repair techs working for them, back when we had factories opperating in this country. (Thank you Fianna Fail).

masseyno9

Had the exact same problem with my alfa 156 fob. Radionics or farnell sell the switches. I got the part number off an alfa owners website and they were €1 or €2 each I think.

I found the best way to do the soldering was to add very little actual solder of your own to the board (I was afraid of it getting messy) and just holding the switch in place with a tweezers while having the soldering iron on top of the contact. My thinking was that the existing solder would melt to the contact, which it did, thankfully! A tiny drop on the top of the contact then would be no harm either.

Small-print: It would be advisable to have a spare fob as apparently solder splashes can cause the whole fob to be screwed up. I took a gamble with my only fob and was ok. To be honest, once you're careful, it should be fine, but there is a risk.

Auscast

Thanks for the replies everyone.
I'll call into Peats and see if they can help.

Paddy, the switch is 6mm long.

If Peats can't help I'll contact Radionics and/or Farnell for the switch, and come back on here to see if someone can help with the soldering.

Final option is to send the key to http://www.keyrepair.co.uk/ in Wales.
Google says they do a good job on the key cards and they're not expensive.

DublinDilbert

I have a switch(s) here that would do the job....

If your stuck for someone to solder it on let me know.

zilog_jones

masseyno9 wrote: »

I found the best way to do the soldering was to add very little actual solder of your own to the board (I was afraid of it getting messy) and just holding the switch in place with a tweezers while having the soldering iron on top of the contact. My thinking was that the existing solder would melt to the contact, which it did, thankfully!

Re-using solder like that is not a good idea. The joint won't last. You should remove all the old solder with solder wick or whatever.

JHMEG

Are the legs broken off the switch? Or have the solder joints just broken. It's hard to tell from the photos.

I'd suggest you use hot glue or something to around the switch to take the pressure when you have it re-mounted.

Alun

JHMEG wrote: »

Are the legs broken off the switch? Or have the solder joints just broken. It's hard to tell from the photos.

They look like they're surface mounted components, i.e. no 'legs', that are soldered using a technique called reflow soldering. It's pretty difficult to repair such boards by hand soldering SMD components unless you're used to it.

http://en.wikipedia.org/wiki/Surface-mount_technology

http://en.wikipedia.org/wiki/Reflow_soldering

Eric Cartman

if you need help im around before 3 any day, have switches and have no trouble soldering it

JHMEG

Alun wrote: »

They look like they're surface mounted components, i.e. no 'legs',

It will have terminals of some description, which may or may not be broken off. I've soldered surface mount stuff before, and that fob is very do-able as it's older/bigger components compared to modern stuff.

masseyno9

zilog_jones wrote: »

Re-using solder like that is not a good idea. The joint won't last. You should remove all the old solder with solder wick or whatever.

I had an idea that might be the case, but followed instructions from someone else that didn't mention anything about it so just went ahead with it. (it was also my 1st time soldering!) To be honest, I was delighted it worked, and probably expect it to go again, but at least I'll be able to have a go at it properly next time. It's lasted 2 months of everyday use so far, so maybe I got lucky!

DublinDilbert

masseyno9 wrote: »

I had an idea that might be the case, but followed instructions from someone else that didn't mention anything about it so just went ahead with it. (it was also my 1st time soldering!) To be honest, I was delighted it worked, and probably expect it to go again, but at least I'll be able to have a go at it properly next time. It's lasted 2 months of everyday use so far, so maybe I got lucky!

More than likely it will be fine. Typically you don't need to remove all the old solder to get a good joint, once you apply enough heat and some new solder you'll be grand.

Alun

JHMEG wrote: »

It will have terminals of some description, which may or may not be broken off. I've soldered surface mount stuff before, and that fob is very do-able as it's older/bigger components compared to modern stuff.

Of course it will have terminals of some sort, wouldn't be much of a switch otherwise. I was referring to it not having traditional terminal pins, or 'legs', that would go through holes in the PCB and be be soldered from below, which is what most people would be familiar with if they'd done any soldering at a hobby level.

Anyway, zooming up really close on the right hand photo, it looks like the switch terminals (well one terminal, the other has broken off) protrude slightly beyond the edge of the casing, rather than being hidden completely under it as they are sometimes, so it looks doable, assuming the OP can get the same or a similar replacement switch.

Auscast

Yes, one of the 'legs' on the switch has broken off.
My idea was that if I couldn't find a replacement switch too easily, you could use the iron to melt the plastic and reveal the 'stump'.

It seems a few people here have a replacement switch and the time to help, so 'thank you', I'll be in touch!