Comment by neilv

> I reckon it will be valuable in the future that comes.

If you foresee supply chain or financial difficulties where you are, enough that people will need to keep old machines running...

* Question: Are you thinking for keeping your family's device's working, and maybe teaching them? Or for operating a primary business, or side business?

* If you're currently financially comfortable, you might want to quickly learn what tools and supplies you'll need for several(?) years, and see whether they're currently available and inexpensive where you are. (For example, temperature-controlled soldering irons, desoldering device or braid, a multimeter that has all the features you expect to need, misc. screwdrivers, many sizes and types of security bits, smartphone repair spudgers and suction cups, an assortment of various high-quality capacitors of various specs, an assortment of hookup wire, fuses. Some common parts, like mains power cords, are easy to find from unfixable devices.)

* Repairing power tools and small&large appliances, is a bit different than repairing old radios and televisions, is a bit different than new radios and televisions, is a bit different than older computers, is a bit different than newer computers.

* If this includes keeping old computers working, you might want to think about what kinds, and what parts will wear out and be difficult to cannibalize. For example, some laptop models will need their fans replaced eventually, and then maybe their keyboards. Laptops made 15(?) years ago will soon need new backlight tubes and/or inverter boards, or new panels (possibly LED-backlit, plus the electronics to drive them). Most PCs and laptops will need new thermal compound eventually, especially if you do some kinds of work on them. Fortunately, most PC parts can be cannibalized easily.

* Repairing smartphones requires special parts and supplies, and in some cases might be impossible. You might think ahead to which ones you expect to want to repair, watch (and try to youtube-dl) the tutorial videos, and

* For a business refurbishing old laptops, you might want to start saving repair PDFs now, in case the Internet gets fragmented. For Lenovo/IBM ThinkPad laptops, search for "Hardware Maintenance Manual" and the model numbers.

* Try to avoid IoT, and computers and software that depend on some company's servers to keep running. And move to Linux (such as Debian Stable) if you haven't already. WiFi routers should be running OpenWrt for security and longevity. And consider whether you want to focus on a particular ecosystem of smartphone and tablet (iOS, proprietary Android, "alternative firmware" Android) that you expect to be able to source enough devices for and keep working.