Troubleshooting an Async Firmware Operation Error on the NextSeq 500/550

This error in the NextSeq 500/550 Control Software (NCS) is due to a transient communication issue between hardware components. It usually does not affect run progression or performance.

Possible error messages:

• "AsyncFirmwareOperationCommand timed out waiting for started after XX:XX:XX."

• "While waiting on an asynchronous firmware operation: camera bitmask 111111 Originally caused by: Failed XY Stage."

Troubleshooting steps:

1. If the run is continuing, allow the run to complete

2. After the run completes, review run performance. See Specifications for the NextSeq 500/550 System.

3. Power cycle NextSeq 500/550.*

4. If the system initializes, proceed with the next sequencing run.

If the run fails, or NCS fails to initialize after a power cycle, or the same notification reappears during the next two consecutive runs, contact Illumina Technical Support for further assistance.

*For further information, search for Knowledge Base Article How to Perform a NextSeq 550 Power Cycle

For any feedback or questions regarding this article (Illumina Knowledge Article #1680), contact Illumina Technical Support [e-mail].