I've been pulling the main power connector to stop the popping (larger drivers side connector into box) and reconnecting it a day later, it might work for 1-3 days after this before acting up again. I keep the cover piece with the 2 screws out so I can access it easily BTW. Anyway, it's been bitterly cold up here in the northeast, yet the silver box was burn my hand hot when I pulled it immediately after it started acting up again. Compared to normal when heat is on and unit is unplugged where I can touch it and it's barely warm from air that leaks from heater.I have a '14 Transit Connect with all the symptoms previously mentioned. The only cause I can think of is that I have been running the heat lately (-20F last night - Hello NE winter), the dash where the radio is located gets really hot.
I pulled the radio today, all parts. I inspected everything down to board level. Looked good with the naked eye.
Reassembled. Everything appeared to be working for a while then BANG, POP!! Scared the crap out of me.
I will take apart again tonight and see if I can find a poor solder point...