12-17-2018, 04:02 PM
Had this issue just recently on a botched firmware update. I recovered by downloading the latest firmware from Joying for my unit, extracted all the files into the root of the SD card. Plugged the SD card with USB adapter to the USB port and turned on my car. The unit started to update the firmware and was successful in getting back all the functions.
Hope this helps.
Hope this helps.