HELP! Is my LCD broken?

Remove all of the wires except those going to pins 1, 2, and 3 and then put pressure on the black frame around the glass. If you get the expected single row of blocks then you have a poor connection between the display itself and the PC board. You will notice several places where tabs from that frame protrude through the PC board and you can try twisting them some more to tighten the connection. You may have to melt some solder first.

Also, I have some ribbon cable similar to the type that you are using. Mine does not really make secure contact with the breadboard so that may be an additional problem in your case as well.

Don