r/AskElectronics • u/squeeby • 2d ago
Should this transformer look ‘leaky’?
A Unifi US-8-60W just died on me. It went offline and I went to reset it, the LEDs were on and it looked as though it was working fine. However when I unplugged it and plugged it back in again, there was nothing. No LEDs came on at all.
Had a quick look inside and noticed that the surface mount transformer appears to have some sort of black potting epoxy near the seams. The goop is solid and not sticky so I don’t know if it’s supposed to be like that or not.
I’ve found a few images online of this component and also of someone else’s bricked US-8-60W and they don’t appear to have the same goop.
Is there a way I can test this with a multimeter?
The power supply provides 48V 1.25A DC.
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u/squeeby 1d ago
Welp. I think I killed it more. Everything was testing fine. No shorted caps, nothing shorted to ground that I could find and the heatsink was warm so I guess the Broadcom ASIC was doing something.
Decided to solder a 4 pin header to J9 which I assumed would be a TTL UART, accidentally hit it with 5V VCC from a USB TTL adapter and blew something. The TTL adapter fried too.
Now the ASIC just gets mega hot under the heatsink and one of the POE LEDs is stuck on.
I think it’s dead Jim :(