Disassemble washed key fob?

[jw113]

(Apologies if this has been covered, but the forum search requires words of 4 characters or more, and I don't know what else to call it but a "key fob"...)

My car keys, including the fob for my 2007 V70, spent about 20 minutes in the washing machine yesterday. I immediately removed the battery and used canned air to try to blow out most of the water. I then read about rinsing it in distilled water and then 99% rubbing alcohol, so I tried this (using bottled water rather than distilled.)

Today I tried it with a new battery, and it worked 2 or 3 times then stopped.

Is it possible to disassemble the fob to clean and dry it out? I removed the key end, but can see no way to take the electrical (keys, battery, PCB) end apart.

Thanks!

[jimmy57]

Let it dry for another 48 hours. It may still be OK.

[chrism]

I've heard you should put it in a Baggie full of (uncooked) rice for a couple days.

[jw113]

Thanks for the suggestions. It looks like I'll have to try letting it dry for longer, though I now have the PCB out so shouldn't need the rice treatment.

I found photos of a disassembled fob on another site, with instructions to "gently pry" the case halves apart. So I used a cell phone case tool and started at the seam in the key slot, which worked. The PCB looked dry, but I rinsed it in rubbing alcohol again and blew it dry with canned air. I then tested the switches with a multimeter, and all worked.

So I reassembled the fob and tested, but got the same results as before: the lock, unlock and lighting buttons each worked the first couple of times I tried them, but then they stopped working. Not clear if one was stuck on (did I hear the tailgate lock cycling?), or lack of power, or ?

So I took at apart again and will leave the PCB drying for a couple days. Hopefully I haven't fried some minor component...

[vtl]

At least you have the chip working. If you are handy, you can get used fob for cheap and move your chip to the "new" PCB.

Chip is programmed for you car, but it can be reset if one pin is shortened to ground for longer than some time. That happened with my 02 V70 keys, I had to buy a new fob.

[jw113]

Let it dry for another 48 hours. It may still be OK.

Thanks, this seemed to be the answer, and patience was rewarded. I ended up leaving it apart for about a week, and this time after reassembly it worked normally, and has continued to work since.

[mrbrian200]

I ran one of mine in the washer (pants pocket) accidentally too - went through the entire cycle. It was the new one I just had made so I was a little upset with myself. Initially it didn't work anymore I just removed the battery and cover, shook out any loose water that would come out and pointed a hair dryer at it from about 8 inches away about 15 minutes to approximate being left in a hot car on a sunny day. Worked like a charm. It's a Volvo OE fob/keyblade. Who knows with the Chinese aftermarket fobs.

[packetfire]

I would add that using NO HEAT with a hair dryer would be wisest, as excessive heat can cause several electronic components to fail prematurely. Back in the 1970s, we would roll computer systems (big hulking things, the size of fridges and larger) into 120 F rooms to run them under heat stress, and thereby, force marginal components to fail before we shipped the systems to customers.

So, compressed air is bad, as condensation may matters worse than they were in terms of moisture shorting metal etches and leads, and heat from hair dryers is also bad, as you might "cook" a capacitor or chip.

[Mark638]

Thanks for the suggestions. It looks like I'll have to try letting it dry for longer, though I now have the PCB out so shouldn't need the rice treatment.

I found photos of a disassembled fob on another site, with instructions to "gently pry" the case halves apart. So I used a cell phone case tool and started at the seam in the key slot, which worked. The PCB looked dry, but I rinsed it in rubbing alcohol again and blew it dry with canned air. I then tested the switches with a multimeter, and all worked.

So I reassembled the fob and tested, but got the same results as before: the lock, unlock and lighting buttons each worked the first couple of times I tried them, but then they stopped working. Not clear if one was stuck on (did I hear the tailgate lock cycling?), or lack of power, or ?

So I took at apart again and will leave the PCB drying for a couple days. Hopefully I haven't fried some minor component...

Can you Please Share the Link of the instructions of how to take disassemble the key fob??

[oragex]

Not a good idea to use any solvent or alcohool on these SMD components. Fresh water and let it dry quickly in the sunshine is all it's needed.