OK, I am hoping you guys can help me nail down exactly which component failed. Here's the story: I was swapping out some LED GI lights, lots of turning the machine off and on to see what looks good. As Murphy's law would have it, I am all finished and power things up to play a game and get a really loud hum out of the woofer. (Note: pinball Pro Speakers and Sub installed.) Powered off and on a few times and always got the same thing. The hum would remain until the sub light began to glow and then when the light was full brightness all sound would stop (I think this is build in overload protection doing it's job on the sub.) Note, I can visibly see the voice coil pull in on power up. So I tried, the following: -Left the ribbon cable on the sound board disconnected (no change). -Swapped for my TZ sound board, powered up (ribbon cable left off) - No hum, problem fixed. My thinking is the issue is a board component associated with the sound amplification. Question is which component is the culprit? I reflowed solder to usually culprits and checked for bad traces, all of which as no help. So if it is a cap, which cap do I replace? Is it the amplifier component on the big heat sink? if so, what do I replace it with. Let me know your thoughts. I'll post some pics and maybe a video. Thanks for the help!