great I can put my favorite hat on,
component problems come in several forms, a breakdown in the component itself, corrosion of the contacts caused through dampness, and the one that many people do not understand..the Dry joint.
corrosion is usually easy spotted by a small amount of either white or green deposits on the contacts [both the pins and sockets] the dry joint on the other hand is caused through either heat and or fine dust when you take a component out and look carefully one or more contacts will normally look dry and dark
the usual cure is to clean the pins with a pure lint free cotton cloth gently rubbing down the pins so as not to lift them from the card and causing damage, the contacts can be carefully cleaned in the same manor by putting the cloth around a thin card [so it is thinner than the slot]and gently rub the contacts so as not to catch them in the cloth, then reassemble.
if your PSU is over stressed it will get hot and should shut its-self down without issue, But on very rear occasions they can burn out internally causing internal shorts that then send too much power to the the rest of the components and cause a complete failure of everything [but I personally have only had 2 cases of this in the last 40 odd years] when cash permits stepping the psu up a bit wont hurt