08 Altima 3.5SE audio cutting out - front passenger side

[panbacca]

Hi all,
I am relatively new to the Altima world, but have a question about my 2008 3.5SE.

It just has the regular CD stereo in it, and I've started having an issue with it the past couple of days where the audio from the front passenger side cuts out intermittently.
Eventually it will start working again at random.
Everything sounds fine in regards to the audio - no hissing, crackling, distortion, etc. It's perfect. Except the intermittent cut out of the audio.

To try and figure it out, I took off the door panel to examine the speaker, the wiring and connector. Everything looks fine. Nothing is loose, disconnected or exposed to metal.

I'm starting to now point to the head unit itself possibly having a short, but I'm not sure.
Any other ideas?
Being that a brand new head unit is only $200 from a dealer, I'm not too worried about getting it replaced. But I'd like to explore other possibilities before I go replacing stuff.

Thanks