may be better to him to measure some AAA, AA battery, because it is not evident that his oscilloscope part is working well. may be his input is damaged?
can his device show 1.5v on some battery? or test it with some audio jack, measuring voltage there?
ps…measuring the processor with some voltmeter, is a good way to damage it. imho. processor pin is working - he watches generator signal, and listens(!!!) it via speakers(I doubt he can listen signal if processor doesnt deliver it). but he cant see signal properly on the screen(it is too small).
advice. to have less troubles with measurements on such small elements, bind with scotch tape a sharp needle to the probe, and use needle to touch testing points.