computer won't turn on, motherboard doesn't respond to 'start' button being pressed

[sbeacher]

I came home Friday night to my computer off. I normally leave it on and let it hibernate or whatever. When I tried to turn it on the power button did nothing. Opened the case and my Maximus Hero VIII's LEDs are all on but the 'START' button (which is illuminated) does nothing. Other components in my system which have LEDs are lit (my Kraken X61 and my Grid+ V2) but the case fans don't work (and no case LEDs light up) and my GTX 980 lights don't illuminate (though I am not 100% sure if they would light up without the system being on anyhow)

My PSU (Seasonic X750) fans don't spin up at all but this PSU has like a hybrid mode where supposedly the fan only spins up when it needs it. But I would assume it would spin somewhat at start up?

So how do I troubleshoot this? Is this possibly a motherboard issue? I'd assume PSU but I'm confused because obviously some power is happening since the LEDs on stuff all light up.

This build is just over a year old with all new components except the 980 which was a few years older (and I've since removed it anyhow while testing) and had been running trouble free since I built it (nov 2015) I hadn't made any changes to anything lately. I've never had a build fail randomly like this so I'm not sure what to do or which components to suspect. I have an old alienware system that has a PSU in it but it's not modular and is connected to so many random things in that case that it would be quite a pain to get it out to check.

[sbeacher]

I just did the paper clip test and the PSU fan comes on. Now what?

[sbeacher]

Used a multimeter on all the motherboard pins and the values came out fine.

1. 3.35
2. 3.35
3. 0
4. 5.04
5. 0
6. 5.04
7. 0
8. 5.04 (PWROK)
9. 5.11
10. 12.17
11. 12.17
12. 3.35

13. 3.35
14. -11.96
15. 0
16. -
17. -
18. -
19. -
20. -
21. 5.04
22. 5.04
23. 5.04
24. 0

[sbeacher]

Anybody? I guess my next step is I need to get a speaker to hook up to the motherboard?

Here are the specs to my system:

i7-6700k
Asus Maximus VIII Hero
NZXT Kraken x61
Kingston Savage DDR-2400 2x8GB (in the proper slots)
EVGA GTX 980 Superclocked ACX 2.0
Seasonic 750W 80+ PSU
Samsung 950 Pro 512GB m.2 SSD (os)
Samsung 840 Pro 256GB 2.5" SSD
Western Digital 4TB HDD
NZXT H440 case
NZXT Grid+ V2 fan controller
NZXT IU01 internal usb hub

[NemesisChild]

Have you cleared the CMOS and tried with one stick of memory and in different slots?

Disconnect everything except one stick of memory, PSU, CPU, and hook up the monitor to the onboard GPU.

[sbeacher]

I have tried that but I'm not sure I pressed the clear CMOS button long enough so I'll try it again tonight. I read you have to hold it 3 seconds? I'm also going to double check the 8 pin CPU PSU cable is good too since due to the positioning of my cooler (in the top) it was a little jammed in there. But like I said I haven't moved the computer or done anything with it lately, it just randomly stopped working.

I also realized I checked the PSU values without any load. What is the best way to test it with a load? Just attach a single fan or something to it?

Also does the 'START' button do the exact same thing as shorting the front end case power jumpers?

[XZEMi]

I would say use a power supply you know works first perhaps borrow one? Remove the cmos battery for an hour with everything disconnected. Remove any and all usb or pcie devices. Use the A2 dimm slot as indicated in the manual. See if it gets you anywhere. It sounds like the power supply has failed (hard to believe considering its a seasonic x750) but it could have been a power or heat related failure due to power surge or lightning rendering the board and power supply a total loss. Is the system on a UPS or connected strait to the wall?

[Alaxang]

I believed the issue here is with the seasonic X750. ( I used to have this issue with my seasonic X1250 previously and had mine rma 3 x ). Symptom : the motherboard standby lighting remain on but when you press the power button on the casing or the motherboard will not kick start the CPU.
Workaround: (use either methods )
1. U can try pressing the ON button either from the casing or motherboard simultaneously "together" with the PSU ON/OFF button (at the back of the PSU) and somehow it will kick start the motherboard/CPU after a while (like pressing ON/OFF ON/OFF ON/OFF at the PSU together with the on button at the casing)

or

2. You power down the PSU or remove the power cord to your supply and try to plug it after 5min or so for the capacitor to drain off. Usually it will kick start the motherboard but the same problem will comes back the 2nd time you off your CPU and leave it on standby mode.

Let me know if the above works for you. if it does, then time to RMA your PSU. or change to another model or brand altogether.

[MajDroid]

Alaxang wrote:
I believed the issue here is with the seasonic X750. ( I used to have this issue with my seasonic X1250 previously and had mine rma 3 x ). Symptom : the motherboard standby lighting remain on but when you press the power button on the casing or the motherboard will not kick start the CPU.
Workaround: (use either methods )
1. U can try pressing the ON button either from the casing or motherboard simultaneously "together" with the PSU ON/OFF button (at the back of the PSU) and somehow it will kick start the motherboard/CPU after a while (like pressing ON/OFF ON/OFF ON/OFF at the PSU together with the on button at the casing)

or

2. You power down the PSU or remove the power cord to your supply and try to plug it after 5min or so for the capacitor to drain off. Usually it will kick start the motherboard but the same problem will comes back the 2nd time you off your CPU and leave it on standby mode.

Let me know if the above works for you. if it does, then time to RMA your PSU. or change to another model or brand altogether.

I know this is an old thread but your post saved me, thank you very much 🙂

[Bruce82hki]

MajDroid wrote:
I know this is an old thread but your post saved me, thank you very much 🙂

So If this is issue should rma psu? I have Theese issues with corsair hxi1000i
Driving me to madness to figure out what is the issue

Like earlier stated i have tested also psu and works fine But on this built
Has this issue would not like crawl every time under the desk to power off power on psu just to use computer😅Â*