Nano Biscotte crackling sounds

[Gnar-Gnar Gin]

My friend and I are wiring up our sabers tonight, and my buddy's NB v2 makes a continuous crackling noise as soon as power is connected.

I checked his wiring, the solder joints all looked ok to me, and couldn't find any points of shorts under the magnifying glass. We put my sound card in, still crackles. applied power without a sound card, still crackles. I'm pretty stumped here... everything else on the saber works fine, FoC is fine. Main LED is fine, both accent LEDs are fine. you can even hear the sound font, and switch between fonts. but theres always a very loud crackle... I've tried resoldering the speaker leads, and still no luck...

Battery is charging at the moment, the only thing I could think of is a low battery.

here are some pics of his board:

IMG_2074.jpgIMG_2074.jpgIMG_4844.jpg

could it be a bad board?

*edit* i know the solder looks connected in the photo, but it's not... *edit*