Different CPU temp for power from microUSB or headers PINs

[hwdev]

Hi,
we are experiencing a strange issue:
- if the NanoPi NEO board is powered by microUSB the temperature of the board stays around 70C
- if we connect the same power supply to the header pins, the temperature of the board goes up to 90C
Attached is a RRD graph we create reading the board temp from /sys/devices/virtual/thermal/thermal_zone0/temp

Powers.png (51.76 KiB) Viewed 8722 times

Any idea why ?

[mnxford]

I would also like to know the reason behind this different temperature readings on two different methods of powering the nanopi.

[mnxford]

bump