key fob components

[DannyLee]

I have a rather odd request. My two-button remote key fob isn't working well. In the past it has been repaired since one of the buttons fell off! - probably due to the battery getting low and someone pressing harder and harder.

Looking at the printed circuit board under an eyeglass, I can see that one of the little surface mount components is missing. I can see that it was once there but has dropped off, maybe when it was repaired.

Now, I'm an electronics engineer so I can fix it of I know what the component was.

I wonder if anyone is prepared to take a close-up photo of the pcb inside their fob - the side with the push button switches - from that I should be able to determine if the component was a resistor or capacitor, and from the tiny number printed on the top of the component, what the component value was.

The attached file shows a close up of my pcb with the missing part.

Your help would be greatly appreciated.

Danny

[efahl]

Danny, mine's got a 104 cap there.

Eric

[DannyLee]

Danny, mine's got a 104 cap there.

Eric

Eric, that's great. I'll give it a try.

Don't wish to doubt your abilities but you're sure it's a cap?

Some of the other caps are buff coloured and have no marking. If it's black and says 104, I would have guessed it's a 100K resistor.

The 4Gt marking on the transsistor indicates that its a BC860 (PNP general purpose) so the missing component is across the emmitor and base. It's just that I can't think why one would place a cap there - also 104 for a cap would be 100nF and in a 0402 package that is a high value.

Any confirmation would be appreciated. Rather shocked by the response actually.

Danny

[wrljet]

What year car is that remote from? The ckt board in mine has almost

nothing on the pushbutton side. 99% of the circuitry is under the battery

holder.

[DannyLee]

What year car is that remote from? The ckt board in mine has almost

nothing on the pushbutton side. 99% of the circuitry is under the battery

holder.

This is a 1999 996 cab, so one button is for the hard top.

Danny

[wrljet]

What year car is that remote from? The ckt board in mine has almost

nothing on the pushbutton side. 99% of the circuitry is under the battery

holder.

This is a 1999 996 cab, so one button is for the hard top.

Danny

Ahh, mine is 2002, so different remote.

I'm an EE also, and w/o having seen anything other than your photo

and post I would agree, a resistor from emitter to base makes more

sense. And generally caps in that small size are tan/buff color and

are not marked.

Bill

[Tool Pants]

I thought a US 1999 996 has a one button remote, unless it is a ROW car.

I think you need to state if the car is for the North American Market, or ROW.

Anyway, a mechanic gave me a dead remote to play around with it, so I do not know for sure if it is from a 986 or 986 or what year. It is a 2 button remote. It has a colored crest so I'm going to guess it is from a 2002-2004 996.

Does not look like yours.

[wrljet]

I thought a US 1999 996 has a one button remote, unless it is a ROW car.

Anyway, a mechanic gave me a dead remote to play around with it, so I do not know for sure if it is from a 986 or 986 or what year. It is a 2 button remote. It has a colored crest so I'm going to guess it is from a 2002-2004 996.

Does not look like yours.

Mine (2002) looks like that one.

Bill

[DannyLee]

I thought a US 1999 996 has a one button remote, unless it is a ROW car.

Anyway, a mechanic gave me a dead remote to play around with it, so I do not know for sure if it is from a 986 or 986 or what year. It is a 2 button remote. It has a colored crest so I'm going to guess it is from a 2002-2004 996.

Does not look like yours.

Mine (2002) looks like that one.

Bill

The car is European, so may use a different frequency to your 'foreign' US ones and therefore a different pcb.

I tried fitting a 100K resistor last night, but sadly it made no difference.

The problem is this:

I can unlock the car if I press the button on the pcb without the pcb fitted to the key fob - it doesn't work every press, but within three it usually works.

When I fit the pcb into the fob it never works, The led still flashes, but no unlocking. Strange isn't it.

According to the last owner, the push button dropped off, so he resoldered it and it worked for a while, then became progressively worse.

It's not that I'm touching the components when I press the button out of the fob, as It still works with insulation tape covering all but the button.

It's as if the transmission power is very weak, so weak it can't transmit through the plastic of the fob, sounds unlikely to me.

Maybe holding the pcb alters the characteristics in some way.

The battery is a good 3V by the way.

I wonder if Eric is still out there and could send me a picture of his pcb.

Thanks for your time, everyone.

Danny

[DannyLee]

I thought a US 1999 996 has a one button remote, unless it is a ROW car.

Anyway, a mechanic gave me a dead remote to play around with it, so I do not know for sure if it is from a 986 or 986 or what year. It is a 2 button remote. It has a colored crest so I'm going to guess it is from a 2002-2004 996.

Does not look like yours.

Mine (2002) looks like that one.

Bill

The car is European, so may use a different frequency to your 'foreign' US ones and therefore a different pcb.

I tried fitting a 100K resistor last night, but sadly it made no difference.

The problem is this:

I can unlock the car if I press the button on the pcb without the pcb fitted to the key fob - it doesn't work every press, but within three it usually works.

When I fit the pcb into the fob it never works, The led still flashes, but no unlocking. Strange isn't it.

According to the last owner, the push button dropped off, so he resoldered it and it worked for a while, then became progressively worse.

It's not that I'm touching the components when I press the button out of the fob, as It still works with insulation tape covering all but the button.

It's as if the transmission power is very weak, so weak it can't transmit through the plastic of the fob, sounds unlikely to me.

Maybe holding the pcb alters the characteristics in some way.

The battery is a good 3V by the way.

I wonder if Eric is still out there and could send me a picture of his pcb.

Thanks for your time, everyone.

Danny

Having said all that, it does sound like classic battery failure. The battery reads 3.01 volts, when I press the button it drops to around 2.8.

I'll get a new battery and try that.

[DannyLee]

I thought a US 1999 996 has a one button remote, unless it is a ROW car.

Anyway, a mechanic gave me a dead remote to play around with it, so I do not know for sure if it is from a 986 or 986 or what year. It is a 2 button remote. It has a colored crest so I'm going to guess it is from a 2002-2004 996.

Does not look like yours.

Mine (2002) looks like that one.

Bill

The car is European, so may use a different frequency to your 'foreign' US ones and therefore a different pcb.

I tried fitting a 100K resistor last night, but sadly it made no difference.

The problem is this:

I can unlock the car if I press the button on the pcb without the pcb fitted to the key fob - it doesn't work every press, but within three it usually works.

When I fit the pcb into the fob it never works, The led still flashes, but no unlocking. Strange isn't it.

According to the last owner, the push button dropped off, so he resoldered it and it worked for a while, then became progressively worse.

It's not that I'm touching the components when I press the button out of the fob, as It still works with insulation tape covering all but the button.

It's as if the transmission power is very weak, so weak it can't transmit through the plastic of the fob, sounds unlikely to me.

Maybe holding the pcb alters the characteristics in some way.

The battery is a good 3V by the way.

I wonder if Eric is still out there and could send me a picture of his pcb.

Thanks for your time, everyone.

Danny

Having said all that, it does sound like classic battery failure. The battery reads 3.01 volts, when I press the button it drops to around 2.8.

I'll get a new battery and try that.

A new battery and it works - thanks again for all your help.

btw I fitted a CR2032 rather than a CR2025 which is the same diameter and voltage but more life. Fits even though a bit thicker.

[wrljet]

A new battery and it works - thanks again for all your help.

btw I fitted a CR2032 rather than a CR2025 which is the same diameter and voltage but more life. Fits even though a bit thicker.

CR2032 is the correct battery for mine.

Is that with or without the resistor?

I had trouble with one of my remotes once, and it was a battery problem.

New DL2032 didn't work. CR2032 did.

Bill

[DannyLee]

A new battery and it works - thanks again for all your help.

btw I fitted a CR2032 rather than a CR2025 which is the same diameter and voltage but more life. Fits even though a bit thicker.

CR2032 is the correct battery for mine.

Is that with or without the resistor?

I had trouble with one of my remotes once, and it was a battery problem.

New DL2032 didn't work. CR2032 did.

Bill

That's with the added resistor.

I believe CR and DL batteries are the same. DL is duracells name for their cell.

I wonder if your problem was one of the remote 'locking up' as described in posts and that replacing the batt fixed it.

Danny

[wrljet]

That's with the added resistor.

I believe CR and DL batteries are the same. DL is duracells name for their cell.

I wonder if your problem was one of the remote 'locking up' as described in posts and that replacing the batt fixed it.

Danny

No, the original battery was weak. The remote worked but the range was poor.

The new Duracell DL didn't work. Its voltage dropped off considerably when the button was pressed.

I assume it was just no good from the manufacturer. The package was dated and not old.

A new Energizer CR from a different store worked. Much less drop.

Bill

[efahl]

Don't wish to doubt your abilities but you're sure it's a cap?

You absolutely should question my response, it probably is a resistor. I didn't look very hard (bad light, old eyes and crappy magnifier) and I'm not at all familiar with smt parts. :)

Some of the other caps are buff coloured and have no marking. If it's black and says 104, I would have guessed it's a 100K resistor.

My son the photographer has finally relented to pull out a pile of expensive equipment to take a photo. I can now actually see the color!

[DannyLee]

Don't wish to doubt your abilities but you're sure it's a cap?

You absolutely should question my response, it probably is a resistor. I didn't look very hard (bad light, old eyes and crappy magnifier) and I'm not at all familiar with smt parts. :)

Some of the other caps are buff coloured and have no marking. If it's black and says 104, I would have guessed it's a 100K resistor.

My son the photographer has finally relented to pull out a pile of expensive equipment to take a photo. I can now actually see the color!

Wonderful. That's definately a resistor. Thanks for the efforts.

I find it just amazing that one can ask such an esoteric question and fiind the answer within days - I'm now hooked on this site.

Danny