1) Can a modern day computer case become obsolete like computer parts can? Of as long as it's big enough to fit all the components in them you want, you don't have to worry?

2) Once you have a completely assembled build, and you press the power button to turn it on, exactly what part of the build is it activating? Is it possible to assemble the parts such that there'd be nothing for the power button to push into that turns on the PC?

In case anyone's wondering, haven't built anything yet, asking out of curiosity.

ad 1) yes and no, depends on the case (usually no, but it may lack some new connectors in the future)

ad 2) power button is activating PSU and motherboard

1. They can only become ''obsolete'' is if the internal hardware changes so that something on the case becomes inadequate, ie the case has only USB 2.0 ports while you have a motherboard with USB 3.0 or you need more space or cooling. Otherwise, its just a shelf to keep everything in place. Keep the PSU position in mind when you buy though, since those with the PSU mounted at the top can be inconvenient.

2. When press the power button, the wires from that button go to the motherboard, which will then start drawing power from the PSU which also has to be switched on (most people keep it on full time so there is only one power button, but actually that switch is also just as important).

Its easy to do. The power button connects via wires to the motherboard, and it is a manual connection you must attach from the case to the motherboard. Just assemble everything but don't connect the power button wire / cable from the case to the mobo.

Good luck!

Also out of pure curiosity, why would you want to have it that way? I've been instantly imagining some elaborate semi-mechanical steampunkish alternative, a contraption you'd find in Bioshock for instance :D

1) The case is just the outer shell. I remember my dad once put a motherboard directly on a piece of ply-wood and used that for testing. So if you can reuse a case then great.

2) You can forcibly turn on/off the power fairly easily. If memory serves me correctly, red wires are live wires, black ones are grounds; and there's one green wire which if you connect to any ground should start the PSU. This assumes you are working directly with the PSU.

I kinda miss the on/off button where it was one direction/setting to turn it on/off and you could forcibly control if the system was on/off (ATX?), however that does take away the ability of just telling it to turn off and then having it go quiet when it's done shutting down...

Next Weeks News: GOG user found dead next to disassembled PC

Easier said than done. The computer I'd have to either drag out, or manage to move the 500lbs of a desk that's here in front of my wall, or randomly rip out power cords from my UPS to forcibly turn it off...

Although hitting the power for 3-5 seconds on the UPS is easier than all of that, but at that point I might as well do 3-5 seconds on my actual computer power supply button which gives the same result...

I've checked several PSU's to see if they power up at all by shorting green and ground with a paperclip.
Also done in order to power hard drives when I temporarily need to connect a drive (for diagnostics or just to copy data off it) but the machine's PSU doesn't have any more connectors because it's a stupid OEM that provided one extra ATA or SATA plug on the mother board, but no free power connectors.

The standards are described here
https://en.wikipedia.org/wiki/Computer_form_factor
https://en.wikipedia.org/wiki/ATX
Ensure the Case can support the choosen form factor.
There are usually screws to hold the mainboard that can be placed in different spots for different mainboard sizes.
https://en.wikipedia.org/wiki/Computer_case_screws#Motherboard_standoff The mainboard has connectors for:
HDD_LED (harddisc activity)
Power_LED (Shows system is powered on)
Reset_SW (Reset Switch)
Power_SW (Power Switch; ATX SW in the picture)
Speaker (oldskool beeper speaker)

Details can be found in the manual of the mainboard, see attached picture for an example. You can hold the power switch some seconds to force the system off.
If you want a physical solution, the power supply may have a physical switch.. or just pull the power plug.

Oh, I think I see now, thanks.

Yup, the standard PC case has changed numerous times since the introduction of the original IBM PC in the 1980s. There is a massive array of hardware out there though so a case never necessarily becomes obsolete, but rather it may not be able to support certain types of new hardware coming out properly or at all depending on a number of factors.

For example, I have a 12 or so year old Lian-Li aluminum case (PC-65) which is a perfectly good high quality case by any measure. There are tonnes of motherboards and peripheral hardware brand new on the market today which would fit properly into this case and work absolutely fine, so the case is not technically obsolete.

On the other hand, trying to build a high end gaming/enthusiast PC out of this case turned out to be a bad idea. It just does not have adequate cooling built into it and upgrading the fans to the best that can fit into the case would still be inadequate. The motherboard I have is a very tight fit, the PSU I am using was such a tight fit I almost couldn't pull it off, and all of the hard disks are jammed up tight with some of the SATA connectors inaccessible due to elements of the case design being in the way. I'm unable to put the case side on without the temperature going through the roof.

So as far as the hardware selection for this specific PC build is concerned, this case is quite inadequate. A modern build like this really demands a modern case design where the PSU goes on the bottom with the motherboard above it, with 8" fans throughout, lots of air flow, cable management and other modern features to make better use of the hardware.

I think what it really comes down to, is choosing a case that is designed to work well with the hardware one is planning on using. Some people might go the other way and buy hardware that will fit into their case and work. Whichever method one chooses and makes them happy is fine as long as it works really. Personally, having done it a couple times now though - I would not cheese out on a new case when building a new PC, it can cause too many problems and frustrations.

Having said that, I still need to buy a new case for this PC as the old Lian-Li PC-65 is wholly inadequate for my purposes. This spring I'll be pricing out new aluminum cases with modern features and a lot of room to work inside etc. Out with the old and in with the new! :)

If the motherboard doesn't fit, you must insist.

I miss the Turbo button from my 386.

Best button ever, it actually slowed the computer down.

Reminds me I need either a new case or a bunch of new fans. Much rather a new case with big, quiet fans.