A few days ago, while I was compiling some stuff on my ALIX.3D3, I discovered a very high CPU temperature by chance:
M/B Temp: +59 C (low = +0 C, high = +70 C)
CPU Temp: +71.1 C (low = +0.0 C, high = +70.0 C) ALARM
Alix.3D3 with heat sink
I downloaded the datasheet of the AMD Geode LX800 CPU to check which temperatures are OK. On page 598 I found that my model (ALXD800EEXJ2VD) is fine for temperatures from 0 °C to 85 °C. Anyway I looked in my spare part box if I could find a suitable heat sink and fortunately I found a 40mm x 40mm x 9mm one. So I ordered some thermal adhesive and installed it.
The manual of the ALIX.3D3 board mentions a lot of pin descriptions of all pin headers on the board. J8 interfaces the SMBus of the AMD CS5536 Geode companion (which is compatible to I²C if bus speed is below 100kHz, see Maxim’s Appnote for detailed comparison). So why not add additional I²C sensors. As an example I connected an LM75 temperature sensor.
First of all we need to add some pin headers to J8 found on board next to the USB port. Continue reading
LM86 on ALIX.3D3
The schematics of the ALIX.3D3 mention a temperature sensors LM86 on page 2 which external sensors pins are connected to the TDP/TDN pins of the Geode LX800 CPU. So this sensor should be able to measure CPU and mainboard temperature.
The LM86 ist connected by the SMBus (which is compatible to I²C if bus speed is below 100kHz, see Maxim's Appnote for detailed comparison) via the AMD CS5536 Geode companion. Continue reading