Dell C6100 FCB issues. Fans not changing speed.

[RimBlock]

Hi,

I have a C6100 unit that had a faulty FCB. The board has been changed (supplier sent a new one) but now, after the initial burst of speed at boot, the fans refuse to increase speed beyond 1600rpm (IPMI reading) and the processors are hitting 80+ DegC.

• Removing the chassis top does not cause the fans to change speed (it does usually due to lack of directed airflow to the top two nodes).
• Removing a node and not blocking the hole does not cause the fans speed to increase.
• Have tried with BIOS 1.71, BMC 1.33, FCB 1.20 and after regressing to BIOS 1.70, BMC 1.32, FCB 1.18 with no change.
• Connections to the FCB all look fine. The right hdd backplane starts with the correct node from the front power button.
• The bios has been reset to 'defaults safe' to clear anything that may be causing issues.

Any thoughts or testing anyone can suggest.

Thanks
RB

 

[RimBlock]

Well one thing I have discovered is that one of the FCBs I have flashes amber warning lights all the time. It turns out that these lights go off if I connect two PSUs, both with power. This indicates that in this case the warning lights are to indicate that a PSU has failed and it is expecting two to be present.

On looking at the FCB, it appears to have none of its jumpers bridged where as the normal cards I have in most servers have the first 3 jumpers bridged at the fan header end.

I did try bridging these but then the amber lights just stayed on all the time regardless of whether 1 or 2 PSUs were connected and powered. I have not checked the IPMI logs for any error messages after bridging the jumpers.

Does anyone have any idea what the different jumpers do. They are not even mentioned in the C6100 hardware manual but sit next to the single row of pins listed as for the PIC programmer connection in that manual.

This board is different to the one that will not change speeds of the fans when the system is running. The only simularity with that board is that if you remove all the jumpers that came installed the front panel lights flash orange . I have not tried adding a second PSU to that one.

RB