I think when you see stuff like wires soldered directly to pins, its a safe bet the machine was maintained by a hack in the field and pretty much everything that went wrong with it was rigged with whatever parts they had on hand. You're going to find months worth of WTF surprises. The seller was careful not to completely show this machines faults, and I wouldn't trust a dealer that wouldn't make a connector repair like that before selling the game.
There is no reason to have a common used game shipped, its always the way people get burned the worst. This isn't even close to some of the horror stories posted here, but it always goes down the exact same way with the machine carefully staged to barely show the flaws.