Akai REF68 (indicates the panel configuration specifically for Akai models) [User Query].
While specific steps can vary by manufacturer, firmware for this board is typically installed via USB: Download SK506S PB802 1920x1080 Akai REF68 part03 rar
The standby indicator should begin flashing (slowly at first, then rapidly) to signal the update is in progress. Download SK506S PB802 1920x1080 Akai REF68 part03 rar