For official drivers and documentation, you can visit the DNS Support Page for the 42AK9000 model.
Attempt a standard software update via USB first. Download 35019017 1920x1080 DNS 42AK9000 part1 rar
Mstar MSD6369IV (32-bit SoC with 1 ARM core and 1080p Full HD GPU). For official drivers and documentation, you can visit
KPS-L090C2 (utilizing TEA1733 and 4N60L chips). Flashing & Recovery Process For official drivers and documentation