If one cannot use a multimeter, then one has no business opening a computer. Or operating an Ipad or mobile phone. Both are far more complicated and dangerous than a meter. Not an exaggeration. According to your reasoning, touching any automobile battery must also be deadly. Car voltages are higher - therefore are dangerous?
That is absolute rubbish - Following the advice of someone or instructions, or a guide and replacing a slot in part or component on a computer is completely safe and requires absolutely no fundamental understanding of how its electrics work.
You clearly also have no understanding of how voltages work in a car either. The most your going to get from a car battery is a burn if you arc it. It is very unlikely to hurt, or kill you. Only the high voltage xenon headlamp system, or direct spark ignition systems are likely to pose a risk to health, but the chances of that are slim as they're designed in such a way as to protect the public from shocks by cutting voltage long before exposed parts can be touched by the skin.
Give the meter to a 13 year old who can use it even in science class. Multimeter is that ridiculously easy and safe - for how many reasons? Unfortunately many adults would rather fear then learn.
Maybe, but that is the way of the world, most would feel embarrassed to ask, and lets face it, if they knew, they'd have already done it and wouldn't be asking.
A defective power supply can still boot a computer. A good power supply can sometimes fail in an otherwise perfectly good computer. A few of so many examples of why swapping parts creates confusion. And often means two or five times more labor and time. Disconnect nothing. Spend a full minute with the meter. Post numbers. Only then can the most informed reply with an answer that has no doubts.
True, but you're asking too much - people are here asking for help and advice because they're not capable of, or concerned about doing that - If you can't grasp that, then you clearly struggle with understanding the reason for this forum in the first place.
By and large, most of those passing through here asking for advice have a very limited skill set, and are here asking for help because they have no way of working out what is wrong. If they have the mind set to check voltages and then report here they'd have their answer, in which case we probably wouldn't hear from them.
Seriously, do a search and you'll realise what I mean very quickly.
Only way to elicit replies from the best informed means numbers. A meter is by far the easiest, quickest, and least expensive way to get useful numbers. And results in knowledge about how a computer really works.
Anyone who fears a meter has no business opening the cover on any computer. Or using a mobile phone. Or opening the hood on any car where voltages are higher and more dangerous.
Those figures could also be misleading. Not having the voltages doesn't mean a diagnosis cannot be given though, as those that provide advice on here are highly skilled and understanding of hardware faults, and their subsequent diagnosis with limited information and contact.
It is also a tad extreme to suggest someone has no right to open up their computer unless they understand what a multimeter is. I rarely use one, but my customers aren't suffering for it - so that comment is a bit hard to quantify tbh.
I'm not knocking you, the easiest way "sometimes" is to just use a multimeter, but I can count the posts in which the OP has used one with one hand in my 2200+ posts, and countless threads read on this forum. Its just an unrealistic expectation, but if you feel it would be of benefit, your most welcome to do a guide with plenty of detail and pictures that could be used to assist those wanting to diagnose issues.
P.S. Please could you use edit in future rather than double post. Cheers.