I have recently moved, which means I’ve disconnected all my wall warts and had to reconnect them.
Normally, this isn’t a problem - but for one ethernet switch, it was. The box is labelled “Fast Ethernet Switch” with no other markings on the front.
The back has 8 ethernet jacks (ok so far) and a DC tip connector labelled “AC IN”. Great. The DC connector looked like a standard 5.5 mm outside / 2.1 or 2.5mm inside connector.
Markings on the bottom of the box: ES3108CH3 and AES108P. That appears to mean it was an Airnet AES108P, also known as a Pro-Nets ES3108CH3. Airnet appears to be out of business, and Pro-Nets is a Chinese exporter who lists it as “Power: 1w” (but no voltage).
So I cracked the box. The circuit board had a marking I took to indicate centre positive (which would mean not AC in), so I attached the bench supply and worked my way up from 0.
The device needs slightly more than 5v to turn on. I was getting it booting up at around 5.6 v, drawing about 520 ma with 3 network cables attached. I suspect it came with a non-switching wall wart rated for 5v. I tried with a 6v transformer I had handy, and that was too much. (Incidentally, if it’s nominally 5v, that’s more like 2.5w than 1w.)
I fear I have let the magic smoke out now… I had it running and moving packets at a little higher than 5.5 v, but now it boots up partway and croaks. Sigh.
Perhaps this will be helpful to someone else who’s not sure what to use. Seems like a non-switching 5v 1a transformer would be about right. A 1500ma switching 5v transformer I had did not work.
I’m not taking responsibility if this smokes your switch… or burns down your house. Use this info at your own risk. Let me know in the comments if it worked or didn’t.