Arcade machines, like many embedded systems, require firmware updates to fix bugs, add features, or enhance security. However, these updates can sometimes fail due to power interruptions, corrupted files, or hardware issues. To prevent bricking expensive hardware, arcade machines employ several robust methods for firmware rollbacks and recovery.

The primary defense is a dual-partition system. The firmware resides on two separate memory partitions: the active partition running the current firmware and a backup partition holding the previous known-good version. During an update, the new firmware is written to the inactive partition. Only after a successful write and verification does the system update its bootloader to point to the new partition. If the update process fails or the new firmware fails to boot, the bootloader automatically reverts to the backup partition on the next power cycle, ensuring continuous operation.

Many arcade PCBs, particularly those using modern systems like ESP32 or Raspberry Pi cores, incorporate a Boot ROM or a hardware-based recovery mode. This read-only memory contains just enough code to initialize basic hardware and attempt to boot from primary storage. If this fails repeatedly, it can enter a recovery state, often activated by holding specific buttons on boot. In this mode, an operator can connect via USB or network to upload a clean firmware image.

For older arcade hardware, recovery often depends on physical intervention. Operators might need to boot the machine from a replacement ROM cartridge, a USB drive with recovery software, or by using a JAMMA test kit to diagnose the PCB. Some systems also store a "golden copy" of the firmware on a separate, read-only chip that can be used to restore the main system.

The process highlights the critical importance of redundancy and failsafes in commercial arcade operations, where downtime directly translates to lost revenue. Best practices for operators always include verifying the integrity of the update file before installation and ensuring a stable power supply throughout the entire update process.