Symptoms

An issue has been observed with Mellanox ConnectX‑6 LX Ethernet OCP and PCIe adapter cards running firmware versions 26.46.30.48 and 26.47.10.88. When affected, system fan speeds increase and remain fixed at 50% PWM. This behavior has been reported on Dell PowerEdge R760 systems and may affect other server models from the same generation. 

Cause

Engineering is currently investigating the issue and working to determine the root cause.

Resolution

Do not replace hardware components, as doing so does not change this behavior. The issue is easily reproducible. Dell Engineering is aware of the behavior and actively working on a permanent solution. Note: If the primary concern is increased noise due to higher fan PWM, and the customer does not require the fixes or enhancements available in the latest firmware versions, they may choose to downgrade the firmware to the N-2 release. This will help restore normal fan speed behavior and reduce system noise. Steps: Downgrade NVIDIA Mellanox ConnectX-6 LX firmware to 26.44.10.36 Perform a full system power cycle Ensure a flea power drain is performed: Power off the server Disconnect all power cables Press and hold power button for ~10–15 seconds Reconnect power and boot system After completion, fan speeds should return to normal operating levels. This knowledge base article will be updated as more information becomes available.

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