8877 brings the menu you showed and that's the normal behavior. Nothing to be worried about. Use the codes 8888 or 8878.
Exactly I used this procedure:
- I connected the HU to the phone hotspot
- from the phone I launched Remote ADB Shell, then connect the phone to the HU and launched the command
"su @ # zxcvbnmasdfghjklqwertyuiop1234567890,. remount"
- after this action the HU disconnected from the Remote ADB Shell, so I reconnected it
- then I connected the HU to the laptop via USB
- in the SDK Tools folder I launched ADB command from the command line with administrator rights
- then I ran the command "chmod -R 777 folder path" to change the permissions of the system folder where I wanted to put the file
- finally I ran the ADB push command for copy the png file of my interest in this folder
And this is the result:
Buyer beware! I got my unit from this same seller. Paid for a 6g +64 unit, after running AIDA64 turns out it’s a 4gb + 64gb, had to open a dispute after the dispute period was over, luckily got 100$ from AliExpress after sending a video showing radio “specs” against AIDA64 real radio specs, It also said android 11 but it was android 10.
I got Junsun v3pro, and had a problem with the unit fully rebooting every time I turn on the ignition. So, basically it didn't go to sleep and was turning off every time. Junsun told me to change ACC off Sleep count to 1. It actually fixed the issue, although 1 being "sleep off"