The Philadelphia 835 comes in multiple hardware variants (different MCUs: GS, JY, MX, etc.). Using the wrong firmware will break touch or audio.
While updating is generally safe, consider these scenarios where you should a software update: blaupunkt philadelphia 835 software update
A: System update changes Android and the user interface. MCU update controls hardware (radio chip, touch panel, CAN bus). The Philadelphia 835 package usually updates both sequentially. The Philadelphia 835 comes in multiple hardware variants