[SGSW-24040P / SGSW-24040P4] Stacking not functioning with SGSW-24040 (non-PoE) model?

Solution:
1.[Firmware version checking]
a.If there are other SGSW-24040 series in your environment already, please upgrade to the latest firmware from PLANET web site or make sure of firmware version above v1.1 for your existing SGSW-24040 series.
b.Otherwise, there could be known issue to find the correct switch model of your Stacked Switches if you plan to hardware stack them together.
c.Please visit PLANET Web site to download last F/W for SGSW-24040 series.

2.[Stack cable checking]
a.PLANET CB-STX50 or CB-STX200 cables not installed correctly (LEDs on front panel STX1 or STX2 do not light). Check that the cables are inserted correctly
b.The stack cable is PLANET proprietary stack cable, the stack cable is cross-overed HDMI-like cable, and other common HDMI cable can’t be used for the SGSW series.