Maker Bot Replicator 2 Jittering Issues

We (Boys and Girls Clubs) recently received a maker bot replicator 2, but came to find it was broken. It was jittering in jog mode for the x- axis but would not move in the y or z. We then ordered new bot steps and motor wires and replaced the old ones. Now, there is simply jittering in the y- axis, no movement in the x-axis, and functioning movement in the z axis when the device is in jog mode. I would just like some advice on troubleshooting the issue and how I should move forward. Makerbot has informed me the next step would be to purchase a mighty board, but I would like to see alternatives first. Thank You to anybody!