C6300/C6320 - Power button LED flashing amber and System Event Log shows critical error "Hard Drive removed" after AC power cycle.

What is happening:

After an AC power cycle (Full restart), the power button(s) on a Poweredge C6320 server with an expander backplane configuration may be flashing amber and a critical event will be logged to the System Event Log (SEL) showing physical(s) disk(s) removed. More information about the SEL logs can be found in the article: Error Messages in System Event Log and how they can be viewed.

The error message logged is:

"Warning. System Software event: Drive Slot sensor, drive removed"

This is not a hardware issue and there is no need to replace components. This can occur on a C6320 server that has been configured with an expander backplane with less than 24 hard drives installed. There is a communication issue between the fan control board (FCB) and the iDRAC which causes a false event to be logged when the AC power is cycled. This will cause the power LED's to blink amber, and the hard drives removed events to be logged in the SEL. 

To resolve this issue, you should do the following steps:

1. Update the iDRAC firmware to version 2.40.40 or above.
2. Update the FCB (fan control board) firmware. Please contact Dell Technical Support to do this.
3. Manually clear the System Event log (SEL) to clear the error.
4. After clearing the SEL, restart the sled (DC cycle only).