I didn't take it apart but maybe a bad cold solder connection. I didn't get any DC readings before I sent it back. Not sure how long it'll take for diagnosis but curious to see what the issue is.

LFR1100
VP180HP
EP600
M3 In Ceiling x 4
M5OW
M2 - Atmos rears
ADA1500.5
M3 Outdoor Speakers
ADA 1000.8