I have a pair of USB3-HUB7BC which have been working fine for a while now. Earlier this week there was a power outage at my home and after the power came back on one of the two was no longer working.
To be specific, the power LED does not light, even when I press the power button, and the hub does not seem to be detected at all by my computer. After trying some external troubleshooting steps, like exchanging the power transformer with my working unit, switching out the USB cables, etc, I determined it’s the hub itself that seems to have developed a fault.
I disassembled the non-functioning unit and probed it with my multimeter and curiously I can see the 12V supply on the drain pins on the U10 and U15 MOSFETs, and I can see it toggle on and off as expected when I press the power button, indicating to me that the switch and power supply are functioning. (The board is labelled 2014.11.06 H9978-U3-BC1.2-R1.0.)
I also found LED1 – the blue power LED – and I can see a small voltage being applied to it whenever the power is on. Again, this toggles on and off when I press the power button, but the LED itself doesn’t light. I didn’t probe around the rest of the board but when the power is active I can see the expected 5V power on the USB ports.
It seems like something in the digital part of the board isn’t functioning even though the power parts are. I realize that the above isn’t a lot to go on, and I’m sure this is a longshot, but I was wondering is this a familiar failure mode and whether there’s some likely candidates I can peek at next. I expect I’ll be another one of these anyway since I need it for my laptop, but it’d be nice to save this one from e-waste if the problem could be with a simple component I can easily replace. (Obviously I’ll take full responsibility if my attempted repairs make matters worse!)