Would have only made sense if both were Avalon related engineers

Did you somehow miss the part with Lawrence Fishbourne? He provided the necessary direction so Jim could fix the ship. Smdh. Why is everyone so hung up on bitching about tiny details??

I don't think Jim was a mechanic in the sense that he did oil changes at the local garage back home. I think he was more like an engineer. And the original poster's comment contradicts his own statement that "anyone can be a writer."

I agree that they could have had more "useful" jobs. At least Aurora. Writing is wonderful, but it's not gonna save a failing spaceship. Mechanics/engineers like Jim would know at least some machery stuff, which is important to fixing a ship.

If I were Jim, I would have searched the files on the 5000 passengers for the ones that would probably be most helpful to figure out what was wrong with the ship, followed by people that would be nice to build a community. Like a programmer, a pilot, a technician, etc, followed by maybe a doctor, a psychologist, a chef, etc.

I was somewhat annoyed that they referred to Jim throughout the movie as simply a "mechanic", as that implies a technical level job and job duty/activities. Technician level workers, for the most part, perform installation and repair work using tightly defined and taught procedures that are created by people at the engineering level. They're NOT encouraged to be creative. "Just do what's in the book, Bob. The book is always right..." Engineers, on the other hand, are usually involved with research, development, and design level work. They *are* encouraged to be creative.

But at the beginning of the film, when Jim is just being defrosted(so to speak) in his hibernation tube, his status and data display shows: "JAMES PRESTON DENVER COLORADO RATE 2 MECHANICAL ENGINEER".

A Mechanical Engineer is *not* a mechanic. Also, they show that Jim is a bright, curious person who's skills go beyond just the mechanical engineering field. He's obviously also talented with electronics and robotics, and probably many other areas. He appears to be a born "tinkerer".

(Actually, this could be a failure of the script writers to actually understand what the difference is between an engineer and a technician. Also, to top it all off, the skills Jim demonstrates are actually more appropriate to an electronics engineer, not a mechanical engineer. Which might be a further indication of the cluelessness of the script writers in this particular area.)

As for the ship, they state in the movie that the ship carries "spare parts for everything". It has an advanced inventory system, so locating what they need should be relatively easy, plus it's shown that repair manuals appear to be plentiful and easy to get to. Probably even more so once they gained bridge access via Gus's high-level crew wrist ID thingy.

The ship is shown to already possess a very advanced auto-diagnostic and repair system. It was able to keep the main reactor from blowing for over 2 years before it couldn't keep all the balls it was trying to juggle up in the air. And by Jim's own acknowledgement, most repair work in the time period of this move was just unplug-and-replace at the module level. So the idea that Jim was able to locate the correct manual that said:
How to repair main reactor control computer:
1.) Secure replacement core processor module XQ999Z/A1 from storage location 7932/B.
2.) Unplug and discard old module.
3.) QUICKLY Install new module.
4.) Cross fingers.
was not actually all that far-fetched.

After the main reactor's control computer was fixed, that took the load off all the other systems on board. Once Jim brought the auto-diagnostic system back on-line(or it brought itself back on-line), the ship was likely able to fix all it's other problems by itself.