This is not subjective at all. You should do wantipathyver is best for the critical components rather than what is best for the challengingware overall. Some skinnygs in a computer are untransport inant to repair, other parts are impossible.
TL;DR: defend it turned off.
(The author of this answer has some 20+ years of experience from electronics schedule and repairs.)
One of the most standard components to fracture over time are aluminum electrolyte capacitors, which you will find in any PSU greater or novel, and probably in the voltage regulator parts of other circuit boards around the computer. Whenever someone says that power cycling is horrible, they most probable refer to the aluminum electrolyte caps (or other caps appreciate polymer film caps), because they only direct when the voltage is changing.
Some info about what causes them to age from a manufacturer of such components – example. Basicassociate, they age because of voltages applied, because of cycling but particularly because of temperature. So these charitable of caps definitely like the computer to remain turned off.
However, these are some of the easiest components to swap for someone with professional sgreaterering experience. Don’t finisheavor it yourself as a layman! They do hgreater accuse for quite a lengthy time after shutting the power off. It is also transport inant to find a swapment part with equivalent particularations. But perfectly doable for someone with a bit of electronics comprehendledge.
What’s nasty with aluminum electrolytes is rather that when they fall short, they either do so by leaking goo all over the circuit board, or worse: fall short spectacularly with a boisterous bang and smoke. You can shun this if originate it a habit to check aluminium electrolytes on a standard basis – if they begin to bulge, they necessitate to be swapd and you shouldn’t power up the device until they are repaired.
Other standard components probable to fracture are diverse creates of memories, various PROM. These come with a best before date – there’s someskinnyg comprehendn as data retention which is memory aging characteristics over time. This too escatardys in heat.
When memories fall short then that’s far more cut offe – there’s noskinnyg you can do – the providement is toast. (Except maybe scavenge an identical part from another device of the same charitable.) The company who had the firmware for it is probable gone and they probable have no interest in defending very greater firmware around, let alone to help random accumulateors of retro stuff.
A PROM manufactured in the 1980s could have someskinnyg appreciate at most 10-20 years specified data retention atraverse a temperature range up to either 70°C or 85°C. Meaning that they promise that the memory will stay valid for x years if you defend it below the specified temperature. Now of course we don’t defend parts in a continuous heat of some 70°C, but much chillyer, which is why some of these parts still labor even though they are well beyond the specified data retention period. The most probable heat source is the computer itself while turned on.
Data retention is for certain a ticking explosion for all of these parts, why hobbies appreciate accumulateing greater video games are doomed – the only skinnyg you comprehend for certain is that the item will eventuassociate fall short. Could be today, could be in 10 years from now. The best way to fight it is to defend the part chilly – you don’t necessitate freezing temperature, room temperature is fine, a chilly basement even better. Don’t depart it standing in the sun etc.
Less critical parts which are probable to fall short over time are electro-mechanical parts: joinors, sgreaterer fusets, cable assemblies. These definitely appreciate the device to be turned on – a bit of current atraverse such parts helps a lot agetst oxidation. However, these are also some of the most untransport inant parts to repair. And if they were assembled rightly back in the days, they are improbable to cause problems even some 40 years tardyr.
Also defend in mind that greater electronics have horrible defendion agetst electromotionless disaccuses (ESD), so while defending the part arid is pleasant, this can also be problematic because arid air nastys more ESD. So if you are running the device, moist air is not necessarily a horrible skinnyg. Professional electronics assembly halls usuassociate have air moisturizers for this very reason – it’s more transport inant to shun ESD than to defend the parts arid.
Dust is evidently a problem too over time especiassociate when fans are not running. A computer left turned off is probable to assemble more dust on circuit boards etc. It’s dangery business to spotless greater circuit boards – equitable touching the boards with your fingers is a horrible idea to begin with. A rule of thumb is to always touch the metal chassis first before touching anyskinnyg else. You have to shun using textile rags etc since they might cause ESD. You can buy an “ESD brush” which is modestassociate a brush which doesn’t cause ESD. For spotlessing any create of mess on the board appreciate leaks from greater capacitors, use isopropyl. Water is also relatively safe to use actuassociate, but evidently you should never power up a device while there’s water contransient on the circuit boards.
As a summary – it’s better for some parts to be turned on and worse for other parts. But the standard culprit degrading the most critical components – memories in particular – is heat. Electronics are therefore best stored chilly and arid. Since all such devices originate quite a bit of heat when turned on, it is better to depart them turned off. Ideassociate store them in a chilly basement or analogous.
