Most MB makers have a utility enabling read out of Temp, Fan RPM, and Voltage.  It's on the MB CD or go to MB site and download.

On several attempted Resets, my cptr did not shut down and a BIOS warning on the subsequent cold boot of an incorrect CPU frequency.  I verified correct frequency to CPU manufacturer's website.  BIOS settings were OK.

I installed the Asus PC Probe and enabled it.  Received frequent fan RPM, temperature, and voltage warnings.  Most frequent were voltage warnings out of limits.

Likely the Power Supply.   Option was to return to shop and pay labor for no cost PSupply or buy and install.  Opted for the latter as I wanted a better power supply rather no cost, low quality supply.

Installed a 350 watt PSupply with a 120mm fan.  All voltages are now steady and within limits and the new power supply runs much cooler than the old one.  An easy DIY project.  Note plug/wire color orientation on old PSupply before removing connectors.  The new PSupply ATX power connector bundle was nicely factory wrapped.   Plastic ties come in handy to tie unused connectors and wires out of the way and to tidy up connected wires.  Cost delivered including tax $45.

The difference in power supplies is PFC; Power Factor Correction.
The less expensive use passive PFC.
More expensive active PFC.

Did see an active 400W active for $85.  Many ads are silent on type.  If not advertised, probably passive.

My FSP350-60PN(PF) works just fine but if you want the best then active is it.