I purchased four TrippLite Isobar Ultra 4-Outlet Surge Protectors from eBay for about $50.
They were all well-used, but purported to function. Unfortunately, two of them did not. They wouldn’t conduct any power to the receptacles, and displayed a fault LED.
Hence the Video
Fortunately the problems were identical for both, and very easy to fix. There are a pair of very robust and heavy inductors on the PCB that routes power inside the Isobar. They’re not mechanically fastened to the board, except by two relatively small solder joints.
Either in their previous life of hard use or during shipping, they must have experienced some bashing around which caused inductors in both units to become un-moored.
A bit of solder patched them right up.
If you’re looking to repair any of these yourself, this very lengthy video shows you what’s inside and how I went about my repairs.
It was my intent in the video to trace out the circuitry, both on the main PCB and the LED board, but time got away from me. But as promised at the end of the video, here are some high-res stills:
(Click for max size.. but beware that the largest one is 8.6MB and may be slow to render on some mobile devices.)