Repairing robot

I have tried over and over to repair the robo't s arm and leg. I have put the instruction paper in the machine, and as per 2 (different) walkthroughs, pressed the yellow and purple button for the arm (did not work), and the green and purple button for the leg, again, nothing. Would appreciate suggestions, I am totally stuck and about finished with the game.

Thanks!

I can't even find the leg. It is not on the table. I got the arm fixed, I just kept pressing the yellow and purple,