The signs you describe seem to indicate that the Hub is indeed damaged. Chances are only the Buck converter is burned, so if everything goes well you should be able to continue using it with the 3v3 power rail from the raspberry.
In order to confirm the issue:
Plug just the Hub (no KCs, no Raspberry) to the regular cellphone charger with the USB cable. Does the led light? If it doesn't the power source is probably down.
To better troubleshoot it you would need a tester. Please give me the following lectures
- Measure voltage at the test point 10 (
TP10 near the mini USB).
- Take off the plastic Jumper at
JP1 and measure voltage at the uppermost pin (be careful not to touch others with the testprobe)
- Also measure the other two pins on
If you have never used a multimeter before: you have to select the "DC voltage mode", use one of the probes (normally the red one) to touch the indicated points while you hold the other (normally the black one) on a reference to ground.
In the Hub you will find a reference to ground at the test point 7
TP7 close to the pin header
Once we confirm the problem I will give you indications to use the raspberry power rail.
I would love to identify the exact action that caused this issue. We have experienced damage in the buck converter while plugging a KC while the Hub is powered, but just wiggling a cable shouldn't be enough to cause it. Have you plugged the KCs while the Hub was on?
By the way, this problem is caused by an underrated Buck converter. As you know the hardware you received is the same prototype as our team uses to develop the system so it lacks many of the protections consumer grade electronic normally have. This is something that will change with our upcoming official release.