bonee

Russian guy will be your best bet.

It's in the setting and make sure you connect the pink wire to reverse light.

Reinstall the latest firmware

I think it was the 8400 that didn't have the lines... 

Me I would get the 8200. Easy to use and have rear camera lines. 8500 they removed it.  But they added it back in 8600. But I still like the 8200 interface. 8500 and 8600 have wireless AA/Carplay. But rather have it plug in. But wireless is just convenient. And wireless video mirroring from the phone.

8200 is good 8500 has newer interface

Check speaker output setting over BT. Make sure it's on all speakers

We get the map updates faster than Naviextra

Where did you get the card from? I would ask them.

try pressing the reset button. lower right corner

Radio is stuck  in CD reject mode.

Audio cable Is fine

I belive you have to edit the apk to bypass the pasword

I just have free time during the day to look on the site.

What feature are you looking for in debug

no problem

clean faceplate pins

check the ribbon cable

What was done to the radio when it got a result screen. Was the radio taken apart??

you are correct

Disconnected one speaker at a time.

https://www.pioneerelectronics.com/PUSA/Car/NEX/AVH-4000NEX#downloads

Pac TR-1

What firmware 

same way as normal.