Xenon dead - nothing - no power


Hey everyone,

HELP!.. I’m playing around with trying to get two I2C sensors found using an I2C scanner and was having no joy… then all of a sudden my Xenon ‘died’. No LED, no power through my USB meter, nothing. The CHG orange LED does flash when I plug in a USB lead but nothing happens…

What exactly i was doing was i had a temperature sensor on SDA/SCL, address found by I2C scanner. It published fine, all was well there.
Then I added a Temperature and Humidity sensor to D2/D3, which wasn’t found by t he scan.
The Temperature and Humidity sensor was found on SDA/SCL.
No combination of both was found, only what was on SDA/SCL.
Then it just died.

Any ideas?



Check the voltage on the 3.3 pin. If it’s OK check the level on the RST pin. Should be 3v3 in “normal” operation.


What sensors and how were they wired?
If the boards happen to have pull-ups to 5V that would at least pose the risk of damaging the I2C interface on the Xenon since that is only 3.3V tolerant.


Hey - thanks for the replies…

I have 3.3V at 3V3 and and RST.
The sensors are an ADT7420 with 4k7s to 3.3V and a Sensirion STS21 also with 4k7 pull-ups to 3.3V…


Also Windows doesn’t recognise it in the Device Manager - it doesn’t refresh even when its plugged in or out.