Summary
did, and created a video about to show what a great investment decision this was.
Naturally this Juniper EX4100-F-12P switch came without power supply brick for its 48VDC input. Figuring out its pin-out and probing said input showed that the voltage rails had been shorted, giving a first clue as to why this switch had been on sale for so very cheap. Bravely hoping that it would be a straightforward fix, the unit was disassembled.
With a 280 Watt power brick, it’s little wonder that the top of the unit is a one massive aluminium heatsink, including a large heatpipe. Also visible on the lid near the power input was a very-bad-news black skid mark.
From that first discovery the news just got worse and worse, with clear signs of water ingression, rust and corrosion, along with the aftermath of a powered circuit meeting such bad corrosion. After some clean-up it’s clear that some components had violently exploded, ripping apart layers of the PCB and likely parts of traces in those inner sections too.
With no schematics available and no other good repair options via Juniper or anywhere else, it seems that unfortunately this gamble turned out to be merely a pile of e-waste and a few bucks worth of scrap metal. Caveat emptor, once more.
Really don’t see why promoting this is particularly beneficial.
Sure, there’s value in failures. (Pure success doesn’t teach much. But there’s plenty of failures available if you want to study them.
I’d hack the Swissbit in it but it appears to have gotten wet as well.
Not sure why this switch would be worth 4 digits. I have 48 port POE switches from HP that were 300 for a 12 port gigabit switch, even with POE+ is a bit much. I have several HP/Aruba 48 port managed gigabit switches with POE(not + though) that I have paid 20K-ish switches ~10 years ago. 48 ports of 1 Gb PoE, dual redundant power supplies, 8x SFP+ 10 Gb ports, 2x 40Gb uplink ports, managed. And a very nice guy who gives away an unlock-everything license for home-labbers upcycling old hardware. Got my 2nd one for 200-ish. Fully tested. Couple that with some upcycled HP 40Gb Fibre Channel cards reflashed to be 40GbE, got some killer network speed there. Or one heckuva bargain on massive PoE capacity, 48 ports for less than a new 8-port.
Looks like a power supply section. Figure out what voltage it makes and bodge in your own.
He should watch when NorthWest Repair takes a rotary grinding bit to a GPU PCB and digs out burned or cracked layers, then rewires the inner layers one by one. Probably doing it for a power supply section would be much easier.