Hey all, the battery leaked inside this car alarm siren and is having issues. It makes this noise constantly:

and drains the car battery in the process. 2 transistors seem to have burnt out, the resistors are black but seem to be ok, 2 resistors measure around 100 ohms and the Jxx marked resisters are all 0 ohm.

 

iv taken some components off the board. now the alarm siren would not make any noise when locking and unlocking the car but it does sound the alarm as normal when its triggered by ultrasonics or door/bonnet/boot switches. so that means the siren speaker is still working.
the zener diode is busted and im not sure what sort of voltage it would be, not sure if it was for charging the 7.2v internal battery. more pics attached.

 

the capacitors on the board by the battery power connector are 100uf 16v and 100uf 50v. no schematic is available for this siren.
2 of the transistors that didnt burn out still work. TIP32C is the part number for the transistors which i can get replacements for. just the zener diode im stuck on. the through-hole resistors seem to have a body length of 6mm. some pics of how the board is now with the components removed and some clean up done. looks like a single layer board.
is this fixable?

 

Personally I wouldn't bother with it, looks like battery leakage on the pcb, too much burnt damage.

 

i thought the same but cant get hold of a replacement. the part where it still actually sounds the alarm is whats odd. i need to find out if there is a separate side for charging the battery which i can bypass and just use the sound part.

 

removed the sticker of the small chip and its got some markings on it:

12C508A
04/P01V
0113

maybe if i can find a datasheet for this it may give schematic info of whats supposed to be connected to it and how?

 

That chip is. a Pic microcontroller, it will have a programme built in by the manufacturer of the alarm, so it's no use to you , put the whole thing in the bin.!