Computer just switched off at random, for the second time today. This time, it happened simultaneous with a power flux event (the air conditioner halting).

Maybe I need a UPS. :(

Ha ha heehhhh after several days of no problems my computer just shut off at random while I was sitting at it using it, and then less than five minutes later, did it again. Is there a way to get Windows to tell me, after a restart, why the hell it just restarted

Like I understand it might not know why it shuts down but surely if it restarts there's somewhere a record of why

Ah… thanks Windows. Thanks for clearing that up

It's happening now at times it wasn't happening before

I eventually learned to get the data from the "real" event viewer instead of the fisher price baby and this is all it says.

Two references to "Power". I don't know if that means the problem is with the power, or if that's Windows' way of saying "I don't know?".

I did get a core temp log when the computer died last night. The CPU temperature was not high at all at the moment of the reset.

I am terrified of a near future where I spend hundreds of dollars on a UPS, it takes up a bunch of space under my desk, and it turns out not to solve the problem

Every time I buy an Apple computer I eventually have to replace it even though it works and I don't want to replace it, because of planned obsolescence, and every time I buy a non-Apple computer it eventually just breaks

The scariest possible thing that could happen in the next few months is I buy a new mac because Apple forces you to buy a mac to develop for the Vision, then my Windows machine craps out totally and I'm having to use a Macintosh as my daily driver

Okay so everyone has convinced me that probably the problem is my PSU, the computer is power spiking & triggering safeties

My friends who Know Computers say it's important to check review sites like tomshardware or cultist.network & pick a high rated PSU

My current is a ThermalTake GF1 750W gold, the store by me only had a Gigabyte for 850W replacements

Trying to decide whether to buy that, go to Amazon & wait, or contact ThermalTake to replace the old one

In the meantime I'm stuck in Linux

Like the ThermalTake has worked fine for just under two years, nothing obviously changed before the problems started except I swapped my SATA drive for a m.2 one on the motherboard, and that was like a week or two before, then boom problems

So maybe the ThermalTake isn't overloaded, just going bad?

Ohgod I have noidea what I am doing

I have extensive notes of which cables were connected before I pulled the old one out, but I have no Gnosis

The PSU came with three seemingly identical cables, each of which has a single head at one end and two heads at the other end. I think these are interchangeable and I think one goes from the CPU/PCI-E slot at the top of my motherboard with one head left unused, and the other goes from a CPU/PCI-E slot to the 8pin slot by the CPU with one of the cable heads unused.

However, the three seemingly identical cables are NOT identical. See below. But nothing is labeled and there's no parts manifest

Wait, no! There is a parts manifest…on… the box?! That is the least convenient place to put documentation. I don't have room to store boxes. Also, it seems to be wrong. It claims it comes with two of the 8-pin "CPU" cables and four (?) of the PCI-E "split" 6+2 cables, but all I find in the box is three of the 8-pin CPU cables (Except one appears to have the "empty" pin??)

Last time I did this it somehow wasn't this hard.

I feel defeated and incompetent. I can do literally anything (given enough time) with a computer once it is switched on, but I apparently am not capable to plug a cable into another cable.
Me, failing utterly

Someone asked for a photo of the motherboard. Here's above the video card, the video card, below the video card.

The "wide" motherboard connector (first image right side, in shadow) is obvious. Similarly the cable for the video card (image 2) seems obvious. But the CPU connector (first image top right) is baffling me. EDIT: wait maybe I figured it out.

Also I distinctly remember (and wrote down) I unplugged something in the bottom left (image 3 or possibly "CHA_FAN2" in image 1) and I assumed it would be obvious what but now I have literally no idea what it was. I don't think this one could possibly be essential (??) because it's not on the basic plugs lists but I am super angry at myself for not taking clearer notes. Did I hallucinate this?!

I've been stuck on this step for an hour. Just basically a disaster here

This is a really bad moment to realize that the electrical tape is missing
Computer might be fixed now but the only way to know for sure is to just use it for a indeterminate number of hours and after the hours-long ordeal replacing the PSU all I want to do is lay down
@mcc that's a fan connector, likely from a case fan. Nothing to do with the power supply.
@mcc "cha_fan" almost certainly is a power *output*, not an input. To a fan you unplugged to get the cable out of the way?
@mcc CHA_FAN2 stands for chassis fan 2. It's a connector for one of your fans. Most likely the rear fan or for a side panel fan if your case has one.
@mcc that should be a case fan. Probably fine to not have it connected but better to find it.
@mcc It would be a chassis (case) fan -- if all your fans are plugged into the board, you're probably fine (it's not unusual for there to be more fan headers on a motherboard than fans in a build).
@mcc not sure if this helps, but I believe this is the manual for that motherboard. It should have a board layout. https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/PRIME_H270M-PLUS/E12027_PRIME_H270M-PLUS_UM_WEB.pdf?model=prime_h270mplus
@mcc FYI, even though every manufacturer uses the same #%@@ connector on the PSU side, none of them agree on the pinout. Don't just toss the extra cables into a bin. Put them in labelled baggies first. (I didn't blow up a motherboard, but it was hours of frustrated debugging)
@mcc i always buy preconfig systems, best 30% premium ever

@mcc "Chassis Fan 2". Being a 4-pin connection, it's a PWM speed controlled fan connector with RPM monitor.

If all your fans have power, you can totally ignore this.

I think some PSUs can have their fans powered from the motherboard in this way; maybe your old one did?

@mcc It's chassis fan connector so you might have a cable dangling off a fan somewhere - or sticking out of some cable management contraption. It's a very specific connector type newegg.com/p/N82E16812162026

It's not essential but not having the fan operational will rise temperatures.

@mcc The CPU power connector is usually two four pin (2x2 square) connectors on one PSU cable that fit snugly next to each other.
@mcc If you don't got one of those, heck if I know... "Try each one to see if it fits"?
@mcc You can sometimes tell which cable is for the CPU power by checking if any of the 8pin cables split at the end. They are usually 2 4 pin cables stuck together. Then from there, you just have to orient it so that the clip latches onto the motherboard connector
@mcc the motherboard side of the 8 pin CPU connector is in the upper left side of the photo, scarcely visible.
@oblomov yes, that's what I've been plugging into. But for a bit I was confused what to plug into it. But I figured it out.
@mcc @oblomov So does this new PSU not split the CPU connector anymore? If so that's gonna confused the heck out of me.
@mcc I have the same frustrations with modular PSUs. I swear some of them do this on purpose and I fucking hate it
@mcc That’s not your fault. It’s obviously terribly documented ><.
@mcc I feel that. I've been saying for years that I can deal with electrons but not atoms
@mcc seems legit confusing and like the manufacturer just didn't think very hard about the discoverability / readability!
@jplebreton It turns out that one of my 4x2 connectors is in fact the 3x2+1x2 connector labeled on the box, and they just glued the 3x2 to the 1x2, and didn't update the box . I guess there's a little bit of plastic indicating this. Maybe you can break them apart if you try.

@mcc I'd contact the manfuacturer to complain.

A parts manifest on the box is fine, quickly lets you say if you need to buy extra stuff too, but it should be replicated on an info card or manual inside. and, well, accuracy would be nice.

This sounds like someone fucked up at the factory.

@anniethebruce okay. You think I'm actually missing a cable?
@mcc Sounds like it. It's worth contacting support to verify at least.
@mcc can you share a picture of the mobo? The 20+4 should be quite obvious in terms of visibilty. The CPU 4+4 depends on the motherboard. The others are for external cards.

@mcc you probably figured this out already, but CPU and PCI-E cables are keyed differently; you physically can't plug them into the wrong place.

As long as all the power inputs on the motherboard and your graphics cards have a lead plugged into them, you're good to go.

(They're just GND+12V to deal with the power consumption of a GPU, which cannot be sourced through the tiny PCI-E pins from the motherboard. Same for CPU aux connector: extra power over what an old ATX connector supplies)

@mcc box says one CPU cable with 2 plugs and 2 PCI-E cables with 2 plugs each. Whichever one is different is probably the CPU cable... but they're keyed differently so don't panic about it.

@mcc That's because TT is a brand name manufacturer, and they have the budget to label the cables and/or write proper documentation.

This is usually considered expendable and of little value in computer part reviews but becomes essential when you do not install the part at least monthly, and it's not completely trivial.

Modular power supplies fall outside of the category of parts with trivial installation for sure.