List of Standard Fixes for TOMY trains?

Hey guys, I just bought this set (seller photo), and the description says that Thomas didn't work when a battery was put in, although, considering it looks so immaculate for being from the 90's (I think), I'm thinking I could probably fix it. However, it has been a while, and I don't remember a lot of the standard attempts at a fix, so I was wondering if you could help me? Thanks!

Is there a battery corrosion? If there is, it is hard to repair.  
 
pull the motor out of the chassis and use a screw driver and move the gears a bit.  Sometimes the grease and oil make the motor seize.  Thomas is widely available, I wouldn't bother repairing it. 

If you insists on repairing it, I would probably use Percy motor.  Some of the engines use the same type of motor..

I don't know if there's battery corrosion yet. I just bought it today.

[Super]

There are really no 'List' of fixes but once you receive the engine and have a chance to look at it, I am sure our members can help you get him going with ideas of whats wrong and how to fix it.

Thanks Super!

If there is no corrosion that needs to be cleaned off, sometimes you just need to give the motor a nice thwack with the butt end of a screwdriver. Someone else could probably explain exactly why that works, but I like to think it scares the little conductors who reside in there.

Honestly, there are many problems these trains can get, it can range from minor ones like a stuck gear in the motor that only needs a twist to get it going again, and there are serious ones like when the batteries leak in a talking engine and the corrosion destroys the circuit board, I should be able to help you fix some issues but you should look to the YouTuber 'Custom Trackmasters' if none of us can help

Thank you!

Yeah, corrosion is the issue. However, there's no soldering involved, so I think I could bend up a new terminal from metal. I'd just need to buy a bit of metal from the hobby shop near me. Oh, and the corrosion isn't on the motor terminal, which hopefully will make it easier.