WS-12-250A Port 2 Voltage Error

[ynot]

Good day,

My WS-12-250A is drawing ~40V when there's nothing plugged in, when POE is set to 48VH.

It will still power the device (albeit ~40v + voltage drawn from device), but the link capacity is limited to 100mb. This problem is exclusive to only one port.

Ran at 1.3.2, upgraded to 1.3.9, and downgraded to 1.3.8. No change.

See attachment for more detail.




Is there anyway to fix this?

[sirhc]

This is a blown current sensor. Current sensors can get blow when exposed to greater than 80V from either a surge or more commonly a ground potential shift if the the tower ground and service ground are not properly bonded together or you do not have a dedicated ground path more attractive than the Ethernet cable. They can also get damaged from shorted cables but if the port still achieves 1G connection with POE OFF then this was not a cable short damage but either a surge or ground potential shift.

Good posts on grounding are here:
viewtopic.php?f=30&t=188
viewtopic.php?f=30&t=1429

We can repair this type of damage, read this thread on the RMA process:
viewtopic.php?f=6&t=1259