Unless you are looking at walkthroughs that are specifically made for the iPad version, I wouldn't trust the walkthroughs 100%. iPad versions often "simplify" puzzles, sometimes to the point of eliminating them. Even if you cut a wire after the fact, and didn't attach it properly, the game may act like you did everything properly as long as the wires are attached at all. Try continuing as if you'd done everything right. If you're not able to, you'll have to start over.
On the positive side, you're only in Part 1 so starting over shouldn't take that long.
I've had iPad games that messed up near the end, so I couldn't finish without playing the whole game over.