I'm at the part where you have to collect fragments of the mantinence officer's voice through logs to unlock the airlock. I have two fragments of his voice, but I can't find the third. I've searched both the mantinence and security terminals. Please Help!

HK is capable of helping you out. He's just not willing.

It's pretty simple...

 

The first fragment you find, the other two come from the HK droid. You get him to replay the last words of the officer, and then trick him into saying the actual voice code itself

 

It's actually not that simple if you don't have the skills your character needs to trick him or if you don't explore the correct dialog path.

 

 

You either trick him and get the entire playback, get two playbacks from the consoles and then destroy the terminal for more exp, or just destroy the terminal for the quicker route.