Yep, the 500 I got last week. Arrived today, disconnected the 604, wired up the 500, powered up and instantly heard a cracking / popping noise. Whipped the faceplace off the HU for instant power off, returned to the boot to see thick orange smoke pouring out of it!!!
It's sat next to me now and it stinks!
I'm gutted as it was the perfect pairing for the 604 and now I'm in limbo for going active again.