Weird problem.

[HellasTechn]

Hello friends.

A couple of weeks ago a friend brought me an opel car key to change its buttons. the buttons where shorted and the remote operation was not working.
After replacing the buttons and attached battery it was dead. When i looked closer i noticed that the transmitter led lits continiously but it is barely visible. the circuit goed back to normal operation only after i short the pins of one IC it has on. Then it works for a few days and goes dead untill i short it again.

I gave it back to my friend so i dont have the IC name.

How can this be explained ?

 

[Tha fios agaibh]

Key fob? Hard to say. Perhaps when shorting the pins it unlatches (brings voltage to 0) a function that runs the battery down?

Perhaps the buttons are still not working properly? (Releasing)

If the buttons are working, I'd pitch it.
Not really something worth servicing.

 

[Gryd3]

Hello friends.

A couple of weeks ago a friend brought me an opel car key to change its buttons. the buttons where shorted and the remote operation was not working.
After replacing the buttons and attached battery it was dead. When i looked closer i noticed that the transmitter led lits continiously but it is barely visible. the circuit goed back to normal operation only after i short the pins of one IC it has on. Then it works for a few days and goes dead untill i short it again.

I gave it back to my friend so i dont have the IC name.

How can this be explained ?

Tha fios agaibh has a good point...
Something is still wrong, either with an external component which can be fixed, or a flaw in the IC.
The downside here is that it's incredibly common to use purpose built/programmed ICs to keep components counts, size, and cost down... Why build a controller with discrete logic when you can simply program a PIC to do the tasks for you? If this IC is to blame you are pretty much out of luck unless you have a ton of time on your hand to replace the IC and generate/reverse engineer a working firmware for it.

 

[HellasTechn]

In other words it does not worth it...