Computer damaged?
 

Hi all,

I have an issue with my 2004REG Mazda MPV 2.0 Diesel.

The battery turned out to swap polarity mysteriously and it blew out the main 120A fuse. I called in the AA and the lads sent were 2 newbies who has no experience and they tried bridging the fuse until we could perceive a foul smell then they concluded that it has to be recovered into a garage for proper and full diagnosis, that was when the engineer discovered that the battery was the cause of the faults and he has fixed virtually all he could but the engine is just rolling now but not starting. He reckons the computer is gone and needs a replacement but he says he cannot work in it.

I got a shop where computers are repaired/remapped online and need to take out the computer to send to them but I am not sure where it is located.

My questions are:
1. Could it really be that the computer is gone?
2. How do I locate and take out the computer?
3. Can the computer be repaired if this type of situation arises?
4. I live in London, United Kingdom. Does anyone on here know a reliable person not too far away who can help me sort out this issue.
5. I found some being sold on eBay, are these one suitable to replace the computer?
6. What's the idea of the cost to sort out this issue?

Thanks

Dafanzy