These are not as hard things as you make them sound. They are the things traditional sysadmins spent time understanding.

But I am also incredulous by the parent.

I wouldn’t be able to diagnose traces on a motherboard or a defective (but partially functioning) CPU.

I wouldn’t be able to diagnose irregular voltage conditions or drop offs.

The amount of stuff that I know I couldn’t diagnose is absurdly high, but the amount I don’t even know that I can’t diagnose is higher still.

And my job, like the parents, is to drill down and spend time in specifics.