Siren Module

draser · Post by **draser** » 30 Dec 2014, 11:52

I am trying to restore the corroded circuit board inside the alarm module, and looking for a picture of the battery connector area of the board. Mine has a resistor next to the connector burned out and need to see lettering on a good one. Anyone has a siren module laying around, p/n 8637399?

Post by **coflynn** » 30 Dec 2014, 18:45

I had taken photos of mine when it was apart - unfortunately it may or may not have captured the resistor you need.

Here is the album: http://imgur.com/a/fxm1I. Be sure to hit the gear and hit 'view full resolution'. The center part of the image of interest has a few resistor values you can read from around the connector, here's an inline crop:

: S60 Siren Connector; s60image.png (585.69 KiB) Viewed 3117 times

This isn't full-resolution, so see the imgur album and zoom in for a better view.

draser · Post by **draser** » 31 Dec 2014, 08:02

Thank you for the very good picture.

bigbrain · Post by **bigbrain** » 02 Jan 2015, 03:49

coflynn....could you post on your progress. I was going to attempt the same fix but I had more components (and tracks) missing. In the end I bought a module on flea-bay from a breaker just for bits but when I opened it the board was perfect so used that instead. I did find that you can buy self adhesive copper track repair tape. Also I managed to source a replacement battery online...on mine I decided the battery should be placed on the outside of the module where it won't be able to cause damage if it leaks...less secure but if someone wants to take the wheel arch covers off and remove the battery to steal a 10 year old volvo then I think they've earned it. Am just interested in how you get on as I was going to try a similar fix myself.

draser · Post by **draser** » 02 Jan 2015, 15:54

Mine had a small leak right by the batt connector, and the C8 capacitor totally destroyed. I was able to id the cap with the nice pic coflynn posted. After removing what was left of the cap it turns out the pcb was burned thru under there, and a copper trace was gone. After thorough cleaning and checking all components around the burn I could not find another damaged component or shorted out traces. The burned trace was from the one leg of the transformer primary, which was actually receiving batt voltage. So I attached a ceramic 10nf cap by wires just to test. No luck. I tried several other lower value caps w/out results. It seems there's more damage so I'm looking for a replacement pcb or whole siren.

draser · Post by **draser** » 17 Jan 2015, 17:08

End of the story is that I bought this used siren off of ebay, making sure there was a return clause in there. Buying a 10 yr old alarm is risky, so after testing it and making sure it works I cut it open. Sure enough, the battery leaked badly, worse than my original module, luckily it leaked beside the circuit board. The battery pig tail was all corroded and separated from connector. There was minimal corrosion to the pcb, but after cleaning there was no real damage. I did not put a new battery in it, rather I ran a 1 K-ohm resistor from terminal 1 of the module, which is 12 volts. Can't see why someone will remove the wheel liner and cut the wire to steal a 10 yr old Volvo.

bigbrain · Post by **bigbrain** » 18 Jan 2015, 03:09

Thats a good result draser...and lucky to get one that was just on the verge of getting trashed. On mine the guy could confirm that it was working just before removal so there was a fighting chance I thought. I don't think I would have been as lucky going to a breakers where they shelve the parts for months....unless they store them upside-down of course!

beachmedic78 · Post by **beachmedic78** » 18 Jan 2015, 13:31

Good luck! The module I bought off eBay had a good board, the batteries were shot but hadn't leaked much.

z2003 · Post by **z2003** » 07 Jun 2016, 08:15

Could someone help me to determine the C19's rate? is it 1.9PF? I have this cap destroyed on the PCB and I want to restore it.

thanks.