Loudspeaker and [un]lock button not working after screen replacement.

Hey everyone,

I've done 2-3 iPod 4th generation screen repairs, this time unfortunately the volume/lock flex cable ripped. :P I ordered a replacement part, and soldered it back to the board successfully, however somewhere along the way the loudspeaker stopped working. Are there components near the flex cable contacts that I may have accidentally damaged while soldering? I can verify that the headphone jack works. Also, the lock/volume all worked just fine at first, but after a while, the lock button refused to work completely, the volume buttons still work, and I can still get the lock button to work by touching the top contact with a screwdriver. I'm so frustrated with this repair! Everything seems to have gone wrong. Please help!