Does anyone have the service manual or schematics for this loudspeaker?

I checked on Mackie's website and they only have v1 and v2 which are not correct. I've also emailed them about it to no avail.

The problem with this speaker is that when I turn it on, it sits quietly but after a little while (like 20-30 sec) it starts crackling and gradually transitions to a high pitch tone even if nothing's connected and the volume pot is all the way down.

This leads me to believe that it's heat related issue, but I don't have a heat camera to check and nothing...

Re: New Members - please post your introductions here

Hello

I'm from Sweden and got interested in electronics a couple of years ago, starting with Arduinos and such. A lot of YouTube-videos later and I've now succeded in repairing a bass amp, a guitar amp and a stage monitor. At the moment I'm repairing an active subwoofer.