New desktop won’t always turn on

[KcBoomer]

I’m building a gaming computer for a friend of mine and everything is all said and done. The first time I plugged it in, nothing happened. I spent about 20 minutes double checking the wiring and nothing seemed out of the ordinary. Checked some videos for help and tried one that suggested holding down the power button to drain the computer of any residual electricity and it worked right away. I came back later (after unplugging it) and the same thing occurred but this time it took several tries of clearing residual and electricity to eventually turn on. I tried it again (unplugging then replugging) to see if it happened again and it did. Oddly once it turns on so long as it stays plugged in I can reset it as much as I want with no problems, it’s just actually unplugging it and plugging it back in that kills it. Really hoping it’s not a power supply issue. Any suggestions? I don’t want my friend to have a flaky new system.
Specs: 10700k
Gigabyte RTX 3080
16GB trident z royal 3600MHz
1TB Crucial P2
Cooler master 750W MWE Gold

To clarify I don’t mean it won’t boot, it doesn’t turn on at all. No LEDs or anything

 

[Bill_Bright]

Yeah, that holding the button in trick is nonsense. It used to be true way way back with AT power supplies when that front panel power button was connected directly to the power supply via a long wiring harness. But today's ATX power supplies don't work that way. Sadly, the suggestion to hold it in has stuck around but really, all it really does is make your finger tired.

You do need to swap PSUs to verify that one is good - or bad.

You should probably take everything out of the case and assemble it on a large bread/cutting board. Also note that cases are designed to support 1000s of different motherboards. So, it is common for cases to have more motherboard mounting points than boards have mounting holes. And while the ATX Form Factor standard dictates where motherboard mounting holes “can” be on motherboards, it does not dictate where they “will” be. So, one board may have a mounting hole in a specific place while another may not.

A common mistake by the less experienced and distracted pros alike is to insert one or more extra standoff in the case under the motherboard. Any extra standoff creates the potential for an electrical “short” in one or more circuits. The results range from "nothing" (everything works perfectly) to odd "intermittent” problems to "nothing" (as in nothing works at all ). So, if you assemble everything outside the case, use that opportunity to verify you only inserted a standoff where there is a corresponding motherboard mounting hole.

 

[witkazy]

Are You using extention cord? If so, try pluging psu cable directly to wall outlet plus check if it is all the way in on psu side after that to exclude wonky power on button scennario, disconect it from the mobo and try to short pwr + - pins with screwdriver to power Your pc on.

 

[Caring1]

Stop unplugging it and plugging it back in, you might have dirty power from the wall socket that triggers the safety mechanisms of the PSU.

 

[Jetster]

Double check the front panel wiring. You may have a two prong connector oriented 90 degrees off

Hey bill if you hold a power button on a modern ATX board it will signal to cut the power to the board. Try it. Maybe that's not what you meant IDK

 

[DeathtoGnomes]

the OP didnt mention a motherboard? This sounds like the old cold boot issues with Fast Startup in win10

 

[Bill_Bright]

Hey bill if you hold a power button on a modern ATX board it will signal to cut the power to the board.

You are right. That is exactly how it works.

But it is the momentary "pressing" of the power button that causes the contacts in the switch to meet (closing that circuit) that signals the PSU. Not the "holding down" of the button. That does nothing here. And that was what I was referring to.

The front panel Power and Reset button switches are tied to "momentary" circuits. That is, when you push the button, it shorts +5VDC through those two pins, which signals the PSU to power up (or down). And after that signal is sent, the circuit is ignored until the button is pressed again and another signal is received. That is, it does not keep trying to power up or power down.

And, there are no filter or storages capacitors or other devices anywhere in that circuit that can be (or need to be) "drained" of excess voltage. That was my point. That is, with ATX boards and PSUs, "holding down" the button does nothing, but tire out your finger.

There is an exception - kinda, sorta, but not really. In some BIOS Setup Menu, you can set the power button "action" so when you press and hold the power button down for ~4 seconds, it will force and instant shutdown - sometimes useful if the system is totally locked up. But that 4 second action is a "timing" action - it still has nothing to do with "draining" any residual voltages.

Again, years ago, with the AT Form Factor, PSUs used a wiring harness and a power button wired directly back to the PSU. Holding the button down was a common method to drain those big caps. And even today, with some notebooks, holding down the power button can have some results - but then today's notebooks do NOT use ATX compliant motherboards or PSUs so they don't count in this discussion.

 

[KcBoomer]

Yeah, that holding the button in trick is nonsense. It used to be true way way back with AT power supplies when that front panel power button was connected directly to the power supply via a long wiring harness. But today's ATX power supplies don't work that way. Sadly, the suggestion to hold it in has stuck around but really, all it really does is make your finger tired.

You do need to swap PSUs to verify that one is good - or bad.

You should probably take everything out of the case and assemble it on a large bread/cutting board. Also note that cases are designed to support 1000s of different motherboards. So, it is common for cases to have more motherboard mounting points than boards have mounting holes. And while the ATX Form Factor standard dictates where motherboard mounting holes “can” be on motherboards, it does not dictate where they “will” be. So, one board may have a mounting hole in a specific place while another may not.

A common mistake by the less experienced and distracted pros alike is to insert one or more extra standoff in the case under the motherboard. Any extra standoff creates the potential for an electrical “short” in one or more circuits. The results range from "nothing" (everything works perfectly) to odd "intermittent” problems to "nothing" (as in nothing works at all ). So, if you assemble everything outside the case, use that opportunity to verify you only inserted a standoff where there is a corresponding motherboard mounting hole.

That’s an excellent point I’ll do that tonight. I hadn’t even considered that it could be a false stand-off. Ya boy don’t have money to be spending on an additional power supply lol

Double check the front panel wiring. You may have a two prong connector oriented 90 degrees off

Hey bill if you hold a power button on a modern ATX board it will signal to cut the power to the board. Try it. Maybe that's not what you meant IDK

yeah I considered that. I did double check everything there. Oddly the HDD LED cable is missing from the case but I can’t imagine that would cause any issues. Other than that everything is wired correctly according to the manual. I’ll do a full resweep tonight and triple check it though.

the OP didnt mention a motherboard? This sounds like the old cold boot issues with Fast Startup in win10

Mobo is MSI Pro Z490 A. I don’t have windows installed yet. Can’t successfully boot to install it now lol

 

[Bill_Bright]

Ya boy don’t have money to be spending on an additional power supply lol

Beg/borrow from a friend or another computer.

 

[KcBoomer]

Beg/borrow from a friend or another computer.

Ok so update: I did what you said and took it out to check for false stand-offs. There were none but running it like a test bench on the motherboard box it booted up immediately twice. Spent about an hour and a half putting it all back together and boom - booted up immediately. Assumption is something wasn’t hooked in right. Set up windows and was going to install drivers when I noticed the pump wasn’t lighting up so my dumbass turns it off and adjusts the pump cable. Now it won’t turn back on. I’m genuinely at a loss. I’ve built probably 6-7 computers for myself and friends and have never encountered anything like this

 

[Caring1]

Are you using the correct type of RGB cables?
Putting 12V into 5V aRGB is going to cause damage.

 

[KcBoomer]

Are you using the correct type of RGB cables?
Putting 12V into 5V aRGB is going to cause damage.

I’m using whatever came with the fans and plugging them into the fan hub. The fan hub used one of the JUSB ports (they are thermaltake). I’ve got 5 fans plugged into it. This shouldn’t be a problem since before I was using the fans that came with the Lancool 2 case. The pump header is ARGB but I’ve got it plugged into a switch that connects directly to SATA. I have 0 fan headers populated. The pump is also plugged into the AIO pump fan slot.

K I solved it. Goddamn outlet is a wash. I tested it with my computer which draws less power and it worked fine but upon trying other outlets everything is fine. If you don’t mind, I’ll be in the corner offing myself. Thank you all for your help, I appreciate it

 

[Bill_Bright]

Glad you got it sorted out and thanks for the followup.

 

[ThrashZone]

Hi,
Interesting term "wash" is it wet

 

[Bill_Bright]

One of the lessor used definitions of wash is for something that is "worthless".