Question New PC shuts off for seemingly no reason ?

[Eydis]

Hello, this is my first time posting as I'm about at my wit's end here trying to salvage a trip and payment to the local computer shop.
So background is that I purchased all the parts from a local computer chain and had paid them the fee to get everything built as a present to myself as my old pc was getting old and I did not want to deal with what to upgrade and opted for a whole new build.
The specs for this build is as follows below:

• CPU - 7800X3D
• GPU - MSI Ventus 3x 4070 12GB
• MOBO - Gigabyte Aorus B650M Elite (mATX)
• RAM - Kingston Beast DDR5 5200 16GBx2
• Storage - WD SN850X NVMe 2TB
• PSU - MSI 8500w ATX3 pcie5 MPG PSU
• CPU Cooler(?) - MSI MAG CORE LIQUID P240
• Case - CoolerrMaster MasterBox NR400 TG mATX
• OS - W11 Pro

This current new build is exactly 2 months old to the date of when I brought it home back from the store. So my problem is that under specific scenarios, my PC shuts down! It full crashes as if I had manually powered off via the button, with no BSOD no error no nothing. Generally during gaming but it has done so as I was installing drivers or even just browsing the web. I've made sure to have ALL my drivers for everything including the major ones like GPU, CPU and BIOS updated as well. Peculiarly enough, it seems to be specific games (some not so popular ones too) or triggers because it always happens around the same time, let me give a handful of examples:

• NFS:Heat - Before I cross the finish line in the tutorial/starting race, then subsequently when I boot again to try, it might not even get past main menu. Now peculiarly I've ran it for a whole day while I was at work once I got into the game and it's fine, but no input just as if I had walked away while ingame.
• Battlefield 1 and V - Sometimes as I load into the game or on main menu
• Diablo 4 - VERY random but it does happen, can be 5 minutes in or after 8 hours
• Remnant 2 - in a specifc spot in N' Erud, near the space zombies, and during cutscene with the alien in the space pond
• Snowbreak Containment Zone - PC Client, specifically only so far when I try to load into Yao's daily fragment grind mission(?)
• Valorant - Generally fine out of the like 20 hours I've played but shut down once after I booted it
• Deus Ex Mankind Divided - Upon loading into tutorial mission after taking a few steps

So these are just a few examples that I can remember at the moment. I know a lot of people upon a quick google search (mostly reddit) will say that it's 5000% the PSU but I don't buy it. I will now list all the thing's I've personally done to try and fix the problem:

• Swapped out a PSU from my old system and connected to the problem unit. Different brand same wattage, still shut down
• Reseated GPU and Ram
• Made sure water cooler radiator mounted corrected (not wiggly or loose)
• Friend told me about changing PBO settings, the something curve, in BIOS which I changed it to negative and 30 count which didn't work. Then I changed the number to 50 and it wouldn't boot so I cleared CMOS
• Tried a new NVMe to make sure it wasn't boot drive
• Ran FurMark for 2 days straight no problem
• Ran Prime95 to test CPU for a few hours no problem

Now I have some notes to share as well, not sure where to put them:

• I've not overclocked anything in my life, unless you count changing the PBO curve setting as my friend suggested
• Ran Cyberpunk2077 benchmark on maxed settings raytraced 1440p for a whole day and no crash, and GPU temps have never been higher than 70°C I believe. Which is why I don't believe it's a GPU Issue
• Ran Diablo 4, NFS: Heat, Honkai: Star Rail, and Black Desert Online all maxed out settings all day simultaneously with no shutdown
• CPU temps are never above 80°C. Ran Prime95 and only then during that stress test I hit 89°C to 90°C
• Played WoW with many addons during a Mythic Raid no problem with all spell effects and players
• Put the new 4070 in old rig replacing a 1070ti with no problems or shutdowns so once again I don't think it's GPU problems

So now, I guess the question is if it's my CPU or motherboard is the part of failure, and if it's just faulty hardware in some part or incompatibility which I didn't research enough because of my own negligence. Not sure if this is enough or the right information to have given but it's been very frustrating being seemingly OK for a brief moment of reprieve just to go and start up a game only to have the room fall dark and silent as the system turns off without warning or error.
If it seems like I should just send all my parts to RMA or repair then so be it, or if I need to buy more compatible parts I guess I will have to.
This is my tin foil

Spoiler: conspiracy theory

conspiracy theory but what if the people I paid money to build my pc sabotaged it because I didn't buy their protection warranty plan lol.

Either way of course if I could figure this out now rather than bring it in for them to RMA it for me and return it around 6-12 weeks would be amazing

Thanks so much in advance if there is any input!!

 

[hedwar2011]

Just curious...Do you have it plugged into a battery backup or UPS (uninterruptable power supply)? What kind of surge protector do you have it plugged into? Do you have other things plugged into the same surge protector and do they experience issues?

Only reason I mention this is I had an incident with a customer once where they were using an older surge protector and a few of the outlets were controlled against power surges. They were experiencing similar issues as you. Long story short, they would ramp up their usage on their PC and it would shut off completely. Come to find out after some testing, the PC was tripping the surge protection on the power strip itself.

 

[Eydis]

Just curious...Do you have it plugged into a battery backup or UPS (uninterruptable power supply)? What kind of surge protector do you have it plugged into? Do you have other things plugged into the same surge protector and do they experience issues?

Only reason I mention this is I had an incident with a customer once where they were using an older surge protector and a few of the outlets were controlled against power surges. They were experiencing similar issues as you. Long story short, they would ramp up their usage on their PC and it would shut off completely. Come to find out after some testing, the PC was tripping the surge protection on the power strip itself.

I have a pretty old surge protector plugged into the wall plug with no backup battery or any of the sort. Pretty sure I dug this out of the closet and it's from like 10 years ago probably, although I haven't personally used it a lot. I'm just not sure as I have other electronics (like the monitors and routers) plugged into it and those stop. On top of that, sometimes it goes out instantly and other times I can be on either gaming or doing nothing for more than half a day no problem. Just seems like specific triggers in specific games. Like some of the problem games nothing during idle! so I have no idea maybe I just RMA it and hope that it does something and wait in dread.. (or get a new mobo and more parts and toss everything else into an ITX build as I believe its faulty mobo 🙁 )

 

[realpao]

Try any other PSUs with more wattage,

 

[hedwar2011]

I have a pretty old surge protector plugged into the wall plug with no backup battery or any of the sort. Pretty sure I dug this out of the closet and it's from like 10 years ago probably, although I haven't personally used it a lot. I'm just not sure as I have other electronics (like the monitors and routers) plugged into it and those stop. On top of that, sometimes it goes out instantly and other times I can be on either gaming or doing nothing for more than half a day no problem. Just seems like specific triggers in specific games. Like some of the problem games nothing during idle! so I have no idea maybe I just RMA it and hope that it does something and wait in dread.. (or get a new mobo and more parts and toss everything else into an ITX build as I believe its faulty mobo 🙁 )

Could very likely be the PSU or it might be the power strip. Get a new power strip and try that.