I swapped the battery out of my key fob and did the programming sequence but none of the buttons work and now my car won't start / crank. I've tested the car battery and I hear a click when I turn the key to the 4th position in the ignition but no crank or start. I think the "new" battery might be faulty. Also not sure if I ruined something called the "immobilizer chip" on the key's logic board. I've attached images of the board with the "new" battery. I noticed I damaged the copper rentangular piece and around the pins I soldering seems a little burnt. Did I ruin the keys?

 

The immobiliser chip is a small black piece in the fob but not on the board, if you have not put this back in fob it won't work

 

what year is your car? might be able to get a fresh one from the dealer

 

^^^The OP's key FOB appears to be the facelift ('05+), three button(?).
Unfortunately if it's an early '02 - pre-facelift '04, 2wo button FOB, (from my experience), they are NLA from the dealer. Most dealers I'd contacted, NLA and do not have the software (or unwilling), to reprogram older model keys. At least in my case.
If you still can't get your key to work - You may want to contact the Mini Key Doctor via email:
minikeyhospital@outlook.com
or visit:
www.minikeyhospital.com
Bruce maybe able to resolder anything on the logic board that may have broken loose.
Good luck.
Please let us know what you discover.

 

This is a duplicate post, couldn't get it removed. It is for a 2005 R50. I replaced it with keys and a cheap key programmer off Ebay (AK90+). Saved a couple hundred doing it this way and I have 3 new keys--2 for the 2005 and 1 spare for the 2006 R50. (Link to original post: https://www.northamericanmotoring.co...n-key-fob.html)

Does anyone know how to get a duplicate post removed? I emailed support last week but haven't heard back.

 

I believe this black piece fell out when I was taking it apart.

 

Try very hard to find it. Otherwise you need a new key.

 

I thought it prudent and helpful to not delete your duplicate post since I felt there was good information as to your dilemma and what steps you took to resolving the problem.
Good info for others in a similar quagmire.