Even if you can't fix it, there is value in tinkering with it. Over the years I've gotten to the point where I understand my limits, when I might be able to stretch those limits, and when to call in the professionals or just chuck it and buy a new one. Even when I can't fix it myself, I have a general idea of what's wrong so I can be much more confident in my decision to replace it; and if I end up calling in a professional, I can be confident I won't be getting ripped off.
The internet has also helped a lot. Specifically, a lot of howto videos show common gotchas, which in the past are the things that have usually caused me to either give up or to turn a $10 repair into a $500 replacement by making things worse...
Lemme second this comment. Everything you say is good.
One thing to keep in mind is that you need to understand when things can be dangerous. Like old tube-based equipment.
I still have a screwdriver that has divots scarred into it from discharging a couple of 500V can capacitors in an old (solid-state) stereo. Now, that's a great lesson... discharge caps if you're not sure about them, and I am glad I learned it.
I'm also quite glad that I did that on purpose with a screwdriver and not on accident with my finger.
I'm even more glad that I did some basic research to know that giant caps ougtta at least be thought about if you're gonna peek around in that kind of stuff.
Completely agree. You need to be careful about capacitors. Generally, a YouTube video will warn you about a part/product you need to look out for. I replaced the run capacitor on my central air unit for $10 and saved hundreds of dollars in repair costs. It's been years and the thing is still running. Just had to watch instructions on how to properly discharge the capacitor.
Having been shocked enough to have a mini PTSD episode when seeing a flyback transformer, did anyone actually die from a normal cap discharge? Unless it's a large subwoofer capacitor, the stored energy is not enough to do deadly damage, even if it's in the thousands of volts, in my experience...
One thing that has been a godsend for me was a scan tool for my car. Not a lot goes wrong with my car, even though it's 10 years old, but being able to ask the car what's wrong when the check engine light comes on is a good way to save some money.
The first time the check engine light came on the car was still under warranty, so I let the dealer take care of it. I didn't own a scan tool at this time.
The second time it happened, many years later, my scan tool told me that it was an oxygen sensor. I know that is beyond my skill level, so off it goes to a mechanic. Since the scan tool told me what was wrong, I knew what to expect and could tell if they were trying to screw me over.
The third time it happened my scan tool told me that the battery voltage was low. That made a lot of sense for a 10 year old car, that had been sitting outside in -27C weather for a while, that still had the factory battery. Fixing that involved a trip to Costco and 15 minutes tinkering in the driveway. I'm sure a mechanic would have marked up the battery and charged an hour of labour, so the scan tool probably paid for itself with this one use.
Youtube is a fantastic resource for any repairs, even if I'm comfortable with doing something I'll often watch a couple of videos first to spot common gotchas.
The internet has also helped a lot. Specifically, a lot of howto videos show common gotchas, which in the past are the things that have usually caused me to either give up or to turn a $10 repair into a $500 replacement by making things worse...