LG42LA620V buzzing sound through speakers

[Chrissygizmo]

I've got an [B]LG42LA620V[B] that is buzzing from the speakers, the buzz gets louder/quieter when turning volume up & down. I've just repaired the backlights & I'm not sure if the tv buzzed previously or if it's something I've done while replacing 2 of the LEDs from 1 strip ...

I will update this post later with photos of boards & board model numbers etc...

Thanks