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.
22
Upvotes
2
u/tes_kitty 2d ago
Have you tested the power supply itself? Those go bad quite often. They measure OK without load but once you plug them into the load, the voltage collapses. It's usually the primary filter cap that's gone bad, but fixing it means cracking open the PSU and working on something that carries line voltage, so not something everyone can fix.