@oldguy52@techhub.social or if you have access to an oscilloscope, the ripple should be less than 100mV on each supply. If there is 1.000V supply, the ripple should be much lower... I do temperature testing on embedded computers to find defects. Heat or cold can shake out defect areas. Heat usually finds bad solder and connections and cold usually weeds out bad silicon. A hair dryer can work in a pinch, but try not to exceed absolute maximum ratings, usually about -40C-+70C for consumer/aircraft or +125C for automotive grade. Sometimes I will take it down to -65C for the troublesome units.