Originally Posted by GemCity970_4S

to my surprise I could not get my ISUDAR CarPlay retrofit to work. I triple checked that everything was correct and that the connections were tight. I took three attempts with no luck. When reinstalling my head unit into the car I would get "FM Stereo" sound to start coming out immediately through the speakers without the ignition turned on. No radio functions would respond, the music (FM Radio) would play at a low volume and adjusting the volume **** gave no response, the screen on the head unit would not turn on.

My guess is the ribbon connectors (that go into the circuit boards) might be bad, I did notice a "dent" in one of those ribbons and they seem like they would be very fragile.

I was able to pull the ISUDAR unit and reinstall the radio (like factory) and everything worked properly again (screen included).

Super strange, not sure if the board is bad, or if the ribbon cable is bad.

Given that I bought it directly from Aliexpress I'm hosed lol.

I do want to take another crack at it so I'll try and buy a replacement ribbon connector if such a thing exists.