Power Button/Volume Button/Screen Repair

I had a friend bring me their iPad 2 with a new digitizer after they tried to change it themselves. It would not work for them after they tried to repair it, so we ordered another digitizer and I removed the lcd and put the new digitizer on and then put the lcd back on just as the guide here says to, when I booted it up before sealing the digitizer down the touch screen worked but I noticed that the power/sleep button didn't turn the device on/off nor put it to sleep and the volume rocker didn't change the volume.

Now as you know from the guide on this site there is nothing with the power and volume that needs to be touched or taken out during the digitizer change. So, my question is, could something went wrong with these 2 when they dropped the device? Should I try changing them out?