Recently my wife E36 alarm keyfob die, I found this super comprehensive guide http://www.bimmerforums.co.uk/forum/...3g-ews-t39173/ and identified my car alarm is 3g version.
Therefore I bought one used keyfob from ebay, same as this BMW 1 3 5 SERIES E36 E60 ETC 3G ALARM RF TYPE WORKING LED 1BUTTON REMOTE KEY FOB | eBay, and followed the instruction to desolder/solder the fob to match my old fob pattern, and the result => doesn't work :(

The seller listed the fob as 'tested ok', I assume it is. What else is the possibility that it won't work ? following is what I guess.

-> I damaged it while doing the desoldering/soldering
-> the seller lie, the keyfob is basically bad
-> there are different version of the IC circuit board in this series of alarm, can some expert confirm this ?