Fujitsu PRIMERGY RX2540 M4 Upgrade And Maintenance Manual page 571

Appendix A
V
CAUTION!
Since the fan module is not included in the minimum startup
configuration, the server must be shut down immediately after the
diagnostic process is complete (POST phase has been passed).
The minimum startup configuration must be used exclusively for
diagnostic purposes by maintenance personnel, never in daily
operation!
Upgrade and Maintenance Manual 571
RX2540 M4