Lenovo Miix 320-10ICR bios.bin BM5668_V1P5A_R bios.bin Lenovo IdeaPad Miix 320-10ICR Schematics BM5668 r1.4A_R Schematics.pdf Lenovo IdeaPad Miix 320-10ICR BoardView BM5668 - BM5668_V1P4_R_N BoardView PDF.pdf