Achim, check the Vcc pins and ones right near it, one of them will be VCore.
There are many 0.8-1.5V pins there usually, you have to test 'em to find out which is which by fluctuating Vcore. Don't keep probe on them for long bursts.

The PSU voltage readings will be the most inaccurate through the HWM IC BTW.

Did you try ASUS AI Gear for your board? http://dlsvr02.asus.com/pub/ASUS/mis...ar2_V10018.zip

Which ITE chip do you have, version I, J or K?

Have you tried using Smart Guardian to get all temp/volts feedback? It should work perfectly for your board since that's the HWM IC you have: SGuardian_it8712_8900135-250.zip