I hate to ask the obvious, but did you try multiple injectors? We had a similar problem with Aruba APs (2 of them) using injectors. Neither would come up while on injector but would on a switch. Thinking the injectors were bad, we swapped one with a brand new, still cellophane wrapped injector and it still wouldn't come up. After many hours of troubleshooting, we thought "what's the possibility that all 3 injectors were bad". Turns out that was the case. Picked up 2 more identical injectors out of stock and both APs came up.
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Jeff Johnston
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Original Message:
Sent: Apr 25, 2025 06:56 AM
From: mertali.guclu
Subject: Instant On AP25 "Device underpowered" Alert
Brand new AP25 with brand new Ubnt U-POE-AT (802.11at) PoE injector fails to work. It says "Device underpowered" and doesn't broadcast any SSID. AP25 keeps blinking red LED. I've tested AP25 with JL683B and JL681A swtiches, works fine with no errors. But current setup requires a PoE injector and i already sold them to my customer. Any help appreciated.