Alarm Siren issue

[slybunda]

Managed to get a replacement siren from a newer model alarm. Its not perfect but works well enough

[slybunda]

scrapyards are full of these things .
personally i wouldn't bother and drive without it . its only there to make noise that nobody bothers about apart from complain .
i did once remove one from a car because it kept going off whilst driving . had to stuff a rag hard against it
to make it quieter it then remove it from the car when it was sounding then threw it in a bucket of water to shut it up .

iv tried 2 of the largest scrapyards in my city and nothing available from them. 10 years ago this would have been very easy to nab but now not even ebay etc has any. dont think anyone needs and aftermarket alarm and immobiliser since all cars came standard with it after year 2000 or so..

[slybunda]

OP cross-posted galore, it's ridiculous:
https://forum.allaboutcircuits.com/t...n-issue.198936
https://forums.overclockers.co.uk/th...ai606.18984085
https://bobistheoilguy.com/forums/th...n-issue.378880
https://www.eevblog.com/forum/chat/c...rm-siren-issue

Must be a relative of treez Sound the siren I need attention.
Is OP fixing it, but says they've bought a new one.
Why bother with the MCU - if it's damaged, you ain't reading any code out of it, and even then the code protection bit is likely set.

Can you fix this siren? Consensus: NO the board is cooked too badly.
Why post all over the Internet?

i dont have a replacement siren for this one. someone is sending me a different type of siren which i may be able to use for parts.
iv worked out the part of this siren thats used for charging the battery, looked like they used zener diodes for a constant voltage charging system, the big diode on the board is to prevent the battery in the siren back feeding to the alarm control box. this should be fixable once i get to look at another siren that uses a similar type of setup to get an idea of whats going where.
no harm in posting in different places since people on different forums dont always go on all the other forums too.

also you missed one more place where its been posted, can you find it?

[petehall347]

scrapyards are full of these things .
personally i wouldn't bother and drive without it . its only there to make noise that nobody bothers about apart from complain .
i did once remove one from a car because it kept going off whilst driving . had to stuff a rag hard against it
to make it quieter it then remove it from the car when it was sounding then threw it in a bucket of water to shut it up .

[redwire]

OP cross-posted galore, it's ridiculous:
https://forum.allaboutcircuits.com/t...n-issue.198936
https://forums.overclockers.co.uk/th...ai606.18984085
https://bobistheoilguy.com/forums/th...n-issue.378880
https://www.eevblog.com/forum/chat/c...rm-siren-issue

Must be a relative of treez Sound the siren I need attention.
Is OP fixing it, but says they've bought a new one.
Why bother with the MCU - if it's damaged, you ain't reading any code out of it, and even then the code protection bit is likely set.

Can you fix this siren? Consensus: NO the board is cooked too badly.
Why post all over the Internet?

[lti]

That's a microcontroller, so it all depends on the program.

https://www.microchip.com/en-us/product/pic12c508a

Damn, I missed page 2.

[CapLeaker]

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?

Its a PIC microcontroller.

[slybunda]

fantastic. any ideas on how the read the code from this chip? can it be done with an arduino uno?

[petehall347]

https://www.microchip.com/en-us/product/pic12c508a

[slybunda]

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?

[slybunda]

pic of the top added here. missing zener is marked Z1 on the board.
my siren had a nickel cadmium battery, later revisions seems to have switched over to nimh battery.

im sure the siren used to sound when battery was removed from car if alarm was armed i think. cant remember that far back and this battery seems to have been dead for a long time.

[redwire]

Only 3-pins then any generic siren could work, just some have (+) trigger others have (-) trigger. I don't know if the siren sounds when unplugged as a tamper alarm? TRIG is normally pulled high at the MCU.
It looks like a crappy constant charging circuit, add that to the Toad lawsuit.
Z1, Q1 are possibly for the switchover to battery power. But you don't want false chirps when trying to start the car batt voltage drops so there must be no tamper detect for power disconnect.
Or the zener Z1 is for charging. Not sure without pic of the top area there.

[slybunda]

thanks for that info above. iv got someone sending me a siren from a cobra alarm so will see how that is inside.
the siren has a single cable which has 3 wires in it that go to it from the control box. the 3 wires are Ground, Trigger and Vbat, so im guessing its just 12v + and - along with a signal to trigger the siren.
im wondering if the zener diode that broke off was for the battery, is it possible it is forward biased when it has above something like 9v and then reversed bias when the car battery voltage drops too low to power and trigger the siren?

[redwire]

I'd confirm Toad's operating instructions- as if there is a mandatory maintenance clause that would hold up in court. Every Toad battery pack is going to leak, you aren't the only person with this happening.

Toad just went to an OEM of car alarms in Asia for the product. Green custom plastic for the horn. Looks same as many others. "Vb" logo would tell more could be Viper. What a UK scam to outsource a cheap car alarm and charge a fortune for it.

What is the wiring to the siren? How many wires? It might simply have the bonnet switch combined in the wiring harness but otherwise is a generic siren.

IMHO the PC board is too burnt up to repair so I would source a replacement or connect an external siren. Look at cheap "SIR1TBB01".
You could draw a siren schematic if you really want to replicate it but the custom IC DIP-8 MCU not known if it lived through the roasting, it drives those transistors. Attached is a generic schematic of your burnt up H-bridge section to help. PCB number Vb 160-2758590

I did see the same eBay replacement battery packs 6 NiMH cells making 7.2V 250mAh for the Toad A101CL and Ai606, Laserline 670, Scorpion SA30, SA35 and Sigma S30, S32, S34. What do their sirens look like?

First time I've seen an alarm sensor for catalytic converters that Toad offer, I wonder how it works one wire only must be a steady ground unless the O₂ sensor or cat bolts being removed.... but they just saw them off here.
Ain't nobody got time to unbolt anything lol.

[slybunda]

Spoke to someone from toad any they not taking any liability saying the alarm should be serviced every year at a cost of £100 which is stupid since over the 20 years iv had it that would be £2000 wasted on alarm service lol.
they offered a siren replacement at a cost of £130 plus delivery which is a total ripoff.
I need to work out what circuitry is for battery charging and what part is for the actual siren operation. May be able to then reverse engineer something onto a breadboard and if it works move it to a perf board or even have jlcpcb etc make a replica.
If i had photos of a working siren with no damage im sure i could do this.
Will have to hit up all the scrapyards i know to see if i can find something.
According to another car alarm fitting company that siren for the toad is not totally unique since they said a sigma or scorpion alarm siren is compatible with the ai606.

[CapLeaker]

You have to wonder if this siren is properly fused- obviously not. Toad Alarm should be liable for damages and the fire hazard. I'd push for a free replacement siren... get them to recall their unsafe product.

I think the problem started with the leaking batteries and it progressed from there. But I agree... I would show that fuck up to the manufacturer too.

[redwire]

problem you have here is that massive amount of burnt carbon which is conductive and needs to be fully removed and leaves you a huge hole in the PCB.

You have to wonder if this siren is properly fused- obviously not. Toad Alarm should be liable for damages and the fire hazard. I'd push for a free replacement siren... get them to recall their unsafe product.

[petehall347]

https://www.toadalarm.com/product/toad-ai606/

https://www.caraudio4less.co.uk/shopping_cart.html?zenid=30hbv53uecildcgphvea7inl93

[CapLeaker]

problem you have here is that massive amount of burnt carbon which is conductive and needs to be fully removed and leaves you a huge hole in the PCB.

[slybunda]

more pics after desoldering stuff, zener diode is toast its broke in half so not sure what to do there. the 2 burnt out resistors seem to both have the same resistance of 100ohm so maybe they are 100 ohm or they both got cooked to the same temp to give same wrong reading? not sure there. some trace damage too looks like a single layer board so not sure now.