Trying to Fix a Suspiciously Cheap Enterprise-Grade Network Switch

When you see a listing for an Ethernet switch whose specification list is in effect ‘yes’, with a four-digit price tag when new, and with the seller asking for less …. Trying to Fix a Suspiciously Cheap Enterprise-Grade Network Switch. This is what [This Does Not Compute] 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.