SG200-50P strange PoE issue

[siddolo999]

Hi, I think i've a very unusual issue.
Specifically i've a PoE issue with the SG200-50P switch and it afflicts the following ports: 5, 6, 29, 30.

If I plug a poe device (yealink t20p) on the port 5, the green led (link led) of the port 5 turns on.

The  yellow led (poe led) of the port 5 is off but the yellow led of the  port 29 turns on (notice that the port 29 is disconnected).

If  I plug a second phone on one of these ports the phones I've connected  are in bootloop (as if the switch didn't supply enough power).

I've tried with different phones, of course.

Another  strange situation happens when I set up the administrative poe status  to "down" (power inline never), but the port goes on supplyingpower .

I've  also tried to upgrade the firmware and to shut down the switch by  disconnecting the wall socket. I've also disabled the green ethernet  feature with no results.

[the.dawning.sky]

I'm also having PoE related issues on SG200-50P.  See my post from a couple days ago.  Is PoE just broke on this particular model or we just got defective hardware?  Wondering if I should do a warranty exchage.

[CorporateVisions]

I'm having the same issues with this exact switch, it's always had flaky POE.  I thought it was my cabling at one point, or old POE equipment, but even directly into the switch I'm having issues getting power to the ports.  Tried everything Pasquale tried, been thinking about doing a warranty exchange as well. 

Equipment in question is mostly Cisco 7960 phones, but also just had the issue with a Meraki (Cisco) MR16 access point.