• Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.
  • The forums have been upgraded with support for dark mode. By default it will follow the setting on your system/browser. You may override it by scrolling to the end of the page and clicking the gears icon.

PSU issue? Power on button not working after power off

Joined
Mar 24, 2010
Messages
5,048 (0.91/day)
Location
València la Vella
I am not sure of the correct expression for an instant power off (as if the plug was pulled from the wall): power off, or power disruption?

Since a short time, if I leave the computer on during the night I find it off in the morning.
Now also, while working, the pc just was shut down instantly.
No reboot, no BSOD. Just instant OFF.

Interestingly, after this happens, the power ON button on the case does NOT WORK.
I have to turn the PSU off, wait until the on-board LEDs are off (discharged mobo), turn PSU on, and then I can use the power on button again.

My Asus mobo BIOS has a Oversurge protection that can turn the pc off if needed for protection, but this does not explain the power on button behavior. Right now when it happened I was writing a Word document and the processor was idling at 1600.

My PSU is Corsair HX750W
My 3770K is overclocked to a turbo speed of 4800 Mhz.

It seems PSU issue to me, but during heavy gaming I have never experienced this problem. Heat or wattage are not the problem, apparently.
I am no electricity expert, so I would appreciate your help.
 
is there a way you can get a peek at the capacitors inside the power supply?

in case you're not sure what you are looking for, here is a picture:
pcpc_3b.jpg

the capacitors are the silver topped cylinders.

they should have a flat top. if they are becoming rounded at the top, they may be failing.
try and grab a picture if you can since that will help.
 
Try and log your voltages? Id be betting on motherboard sensor acting up and turning off when they are out of spec.
I guess the simplest way would be to rule out the PSU ?
 
hey guys i am back and appreciate your ideas!!!

getting into the PSU for now is nearly impossible, and if the problem is there I will just upgrade.
BIOS: good idea also, I will log, but be warned: ASUS AI Suite 2 logs crazy stuff! (I already disabled lots of warnings) Who knows, maybe I should uninstall it!! (I only realy enjoy Fan XPert 2 of that suite)
 
So if disabling logging and even uninstalling AI suite does nothing, I will open the PSU! Would love to use my soldering incapacities! LOL
 
@erixx: what do you mean AI Suite logs crazy stuff? Do you mean it is logging crazy voltages? If so, that's perceisely great information we could use.
 
So if disabling logging and even uninstalling AI suite does nothing, I will open the PSU! Would love to use my soldering incapacities! LOL

I remember having the same issue with an Asus board (computer would shut off and not want to turn back on until all power was removed from the motherboard). Uninstalling AI Suite was the solution for me.
 
That once happened to me with my UP7. I never found the cause and hasn't happened in about a year so I chalk it up to chance but your case seems to be consistent so maybe it's a software issue like FX-GMC points out. Maybe the AI Suite detects something outside the default parameters and shuts off the PC as a preventive measure.
 
thansk to all. yeah, crazy readings is like "warning: -100 celsius, or warning: cpu voltage 70 v."

i am testing some stuff now, but i smell AI Suite is guilty! How or why the biggest mobo manufacturer has such issues, is beyond comprehension!
 
Disabled surge protection (bios) and uninstalled AI Suite except the Fan part. I will leave the PC on tonite, and see...

thank you to all.
 
it wouldnt be the first time AI suite has been buggy! Back in the c2d days it was wonky. Guess they havent fixed it much...
 
This problem could be caused due to any or all of the following reasons:

1 Overclock
2 Faulty PSU
3 Faulty mobo
4 Other

The first thing to do is to remove the overclock and see how it goes - a PC can behave very strangely indeed if the overclock isn't quite stable. Might be a good idea to reset the CMOS RAM and load defaults for this, too.

If that doesn't fix it, then see if you can separate the mobo and PSU ie attach each one to different components if possible and see which one the problem follows.

I guess this might be impractical if you don't have another PC to swap out the PSU with, so you could by a PSU tester for around £20 and check the voltages on the PSU look normal to it. It's not definitive, but will often pick up a duff or out of spec PSU.

Other really could be anything else, so you could try running on the integrated graphics for a bit and see if that makes a difference.
 
AFter some days without problems, while I am was writing here to tell you it seemed all fine now..... PC crashed.... LOL!!!
Keep calm and keep overclocking! ahahahaha!
I have to work now, so I will return later to testing...
 
Last edited:
Yeah, definitely take out that overclock first. :)
 
During last weeks I have been lowering my OC until I totally disabled it leaving all in BIOS at auto. Because I repeatedly got hard resets or not waking up, or case power button not working until I restarted PSU.
but still same issue... time to dismantle PSU or buy another
 
really soudns like just the power switch on the pc needs replacing.

disconnect the power switch, and use screw driver to start pc. check if this causes problems.
 
Thanks but don't think so, it works fine, I just need to disconnect the PSU button, wait until mobo is drained (no active LEDS on) and it restarts fine.
Could the UPS play foolish?

grammar...
 
Last edited:
I was having the same exact problem. The first time I concluded it was my motherboard and RMA'd it. ASUS sent me a brand new one and it worked for a couple weeks before the problem started again. This second time I reformatted the drive and removed everything to completely rule out software or drivers. No such luck. Currently waiting for an RMA'd psu to return and we'll see what happens. Keep us up to date on your issues.
 
Thanks but don't think so, it works fine, I just need to disconnect the PSU button, wait until mobo is drained (no active LEDS on) and it restarts fine.
Could the UPS play foolish?

grammar...
looks like a psu error then.
 
Updates, not good :(

I installed a new high end PSU, removed the UPS, and replaced most of the inside cables.

This morning, again, after leaving it on last night, I found my PC off, and the case power-on button not working (mobo leds = on).
I had to turn the PSU off, wait for the leds to become off, turn PSU on, press case power button and it turned on.

1) I am a bit lost, after testing hardware and software (bios set to stock auto profile)
2) I am not sure how to formulate a google search, maybe this situation has a proper "denomination" in the internets?
 
what about unplug your power cables for few minutes and plug in it again and turn it on
just to check it
 
I appreciate your suggestion, Micropage7, but I am not sure what you mean.

Another question for ASUS specialists: Does EPU chip (activated in BIOS) work without installing the AI Suite (EPU settings inside)? Currently I have it on in BIOS, no AI Suite installed.
It seems a little like the voltage or current in Suspend state is abnormally low, so it freezes the mobo, the power button becomes unresponsive, PC does not wake up: only solution unplug power... !?
 
I appreciate your suggestion, Micropage7, but I am not sure what you mean.

Another question for ASUS specialists: Does EPU chip (activated in BIOS) work without installing the AI Suite (EPU settings inside)? Currently I have it on in BIOS, no AI Suite installed.
It seems a little like the voltage or current in Suspend state is abnormally low, so it freezes the mobo, the power button becomes unresponsive, PC does not wake up: only solution unplug power... !?

when your pc cant turn on when you pressing power button, try to unplug 24 pins cable from your psu to your motherboard, leave several minutes then plug in back then push power button.
does it turn on?
 
OK, will test it next time! Thanks ;)

i hope it works, i dunno, i just think its from motherboard
oops have you tried to reset your bios too?
 
Back
Top