7NNXP temperature sensors

Hi

My PC speaker makes the occasional random beep, so I thought to look at
temperatures using SiSandra (just in case but I guess something else is
causing the beeps).

SiSandra reports:

Board Temperature 36°C
CPU Temperature 28°C
Power / Aux Temperature 58°C

and warns that "Mainboard temperature is too high (is over 50°C)"

What is this "Power /Aux Temperature" as I'm fairly sure that my PSU doesn't
have a temperature sensor? And could a high temp cause the PC speaker
beeps?

Thanks