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Key not working - is it repairable?

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1.9K views 17 replies 7 participants last post by  Kierownik  
K
#1 ·
Hi everyone.
So one of my fobs is not working. Can't unlock/lock the car. Car won't start when pressing the "start" button. Car will only start if I hold the key to the steering column and then press start. So it looks like it's not transmitting the signal at all.
I decided to open it and see what's going on inside. What I found is very strange. It looks like one of the chips on the motherboard somehow got damaged. It wasn't done by me, as I was very careful when opening the fob.
Here are the photos of how it looks...
Image


And here's something strange on the the top side of the fob, where the buttons are...
Image


Image


Don't know how this could've happened. Key didn't look like it was opened ever before. I also tried to find pieces of that damaged chip inside of the fob housing but there wasn't any.

Do you think that this is repairable? Or is it dead for good and only the only way is new fob from the dealer? If that's the case, anyone knows how much that will cost?

Thanks for your help!
 
D
#2 ·
A key is a few hundred pound and requires ordering from Germany

Alternatively... maybe a tech specialist can do something?
 
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R
#6 ·
this sounds promising for you
"Pop into Nova Electronics, the Sheffield electronics specialist for a low-cost fix instead. That's because we repair all types of Printed Circuit Board (PCB), one of which sits inside your car key.

So whether it's a broken car key or another electronic device, let our engineers have a look. If it's the PCB (the chances are it is), then we can fix it. And you can pocket the price difference."
 
K
#8 ·
So they replied.
They said that they can't identify the missing component and I would probably have to buy a used fob (perhaps from scrapyard or something) so they could use it as a donor.
It might all together be just as costly as just buying a new fob from the dealer.
 
#11 ·
How did you open the key.

Not being funny but looks like you took a blade too it or a Dremel? Could you have hit that component opening it - you say you were careful but that doesn't look like a sympathetically opened plastic case?

Just to rule out the obvious too, did you try a new battery before butchering it?
 
K
#12 ·
Barney McGrew said:
How did you open the key.

Not being funny but looks like you took a blade too it or a Dremel? Could you have hit that component opening it - you say you were careful but that doesn't look like a sympathetically opened plastic case?

Just to rule out the obvious too, did you try a new battery before butchering it?
Click to expand...
Yes mate, because both halfs of the fob are glued together I had to use a blade to open it. There's no other way to do it. However I was very very careful all the way round. Definitely didn't put the blade too deep. If I phisicaly damaged it then I'd be able to find pieces of it inside of the fob but there was absolutely nothing.
 
K
#13 ·
#14 ·
Its a crystal oscillator.

Looks like the same circuit on here

I cant find the same component on that circuit, but I can find the ATA5833 above it
Thats the RF transceiver.

Looking at the data sheet, and tracing pin 10 on page 5, that seems to route down to the mystery device, it shows as the crystal oscillator.

Using that clue, and the id of the mystery device 24.305, thats a 24.305Mhz crystal in a 4 pad SMD package.

And the data sheet for that seems to fit (4 pads, two not connected, dimensions seem about right)

So thats a £0.46 component, if you can find 1 (rather than buying by the thousand).

Piece of cake to replace if you have the right kit.

Now, the real question. WTF happened that blew a crystal, one of the most solid of solid state devices, into oblivion, and what else did it take with it. I'd be amazed if you could replace that component, and end up with a working ats got to have been one hell of a discharge.
 
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K
#15 ·
Nottsknots said:
Its a crystal oscillator.

Looks like the same circuit on here

I cant find the same component on that circuit, but I can find the ATA5833 above it
Thats the RF transceiver.

Looking at the data sheet, and tracing pin 10 on page 5, that seems to route down to the mystery device, it shows as the crystal oscillator.

Using that clue, and the id of the mystery device 24.305, thats a 24.305Mhz crystal in a 4 pad SMD package.

And the data sheet for that seems to fit (4 pads, two not connected, dimensions seem about right)

So thats a £0.46 component, if you can find 1 (rather than buying by the thousand).

Piece of cake to replace if you have the right kit.

Now, the real question. WTF happened that blew a crystal, one of the most solid of solid state devices, into oblivion, and what else did it take with it. I'd be amazed if you could replace that component, and end up with a working ats got to have been one hell of a discharge.
Click to expand...
Thanks for your extensive reply.
Now that you mentioned it, I started wondering if this is the only damaged component or is there something else.
I'm loosing any hope that this could be fixed.
 
#17 ·
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K
#18 ·
Nottsknots said:

Finding them isnt the problem. This is a different frequency, but theres nothing to suggest what frequency the OPs one was; need to open the CAS to see what the receiver has, as they need to match.

As said, the problem will be what else got fried. And where did the bits go :?: - maybe the key had been opened before, carefully, then glued back together.
Click to expand...
I don't think it was opened before. It looked like factory sealed and opening it took some time and patience. There was no bits or pieces inside at all, just some dust, like something burnt inside, which obviously was that crystal.
 
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