Question Weird startup behavious (delay) (usb input)

rawfiul

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Apr 14, 2018
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Im a bit unsure which part is called BOOT and which is called POST, so ill keep those word aside.

Heres the timeline:
I turn on the wall switch allowing power to PSU
Motherboard light is on
I hit the power button on my cabinet to start my pc
Cabinet, cpu and gpu fans are on, cabinet light is off, video displays no signal
I panic
I wait for 30secs to a few mins - sometimes it starts, cabinet light turns on, display signal is received and i use pc without a problem
If after waiting a few mins i see nothing, i unplug all usb and ethernet
Turn off pc by holding down cabinet power button - the running fans stop
Then hit the power button on cabinet again - sometimes it starts instantly, sometimes after a few secs

Edit: these hacks stopped working. Now the pc never starts. Sent PSU for RMA.


Now, this odd behavious started out of the blue. For all its life, the instant i hit that power button on cabinet, the cabinet light triggered.


Things i have done so far:
Everything in no display troubleshoot sticky
Checked in BIOS boot option to see if boot drive is correct and not set to usb.
Reset bios settings (there was nothing to reset)
Checked windows startup delay time and set it to 0
Some posts said their Asus mobo had a BIOS Flash button that was accidentally depressed by the wrong I/O panel which was causing similar effect on their pc (i dont have bios flash button on my mobo)


I have a feeling it has something to do with my PSU. Sadly i dont have access to any spare or extra parts for testing



Specs:
ASUS B360M - K
Corsair 8GB DDR4 2400 X 2
i5 - 8400
ZOTAC GTX 1060 6gb Amp
Corsair CX 450M (RMAed once)
Windows 10 X64
 
Last edited:

Darkbreeze

Retired Mod
POST is the process that happens when your BIOS/CMOS runs through it's hardware checks to initialize all the hardware and make sure it is all running normally and as expected, and make the necessary adjustments if there has been any change to the hardware configuration.

Boot is what happens AFTER the POST process is complete, and entails loading up the necessary files and drivers into memory so that the operating system can run.

In the future, do NOT cut power to the power supply by having it switched and turning that switch off and on each time you want to power up or shut down. It is BAD for the power supply to constantly have it's power cut on and off all the time, even if the system has already shut down. Simply leave power connected to the power supply and just shut down normally using the start menu options in Windows. Once you click shut down, that's it. Leave it alone after that until the next time you come back to it and press the power button to turn it back on. Or, simply put it to sleep using the start menu options each time you are done and then just come back and touch the keyboard or move the mouse. It's faster and uses practically zero power while in sleep state.

Try this.

With the computer shut down and the power cable disconnected from the wall (Or the switch on the back of the PSU flipped to the "0" position)

Completely remove the graphics card from the motherboard. Don't just unplug it from the monitor, take it totally out of the board.

Then, plug your display cable into one of the video outputs on the back of your motherboard.

Plug the power cable back into the power supply (Or flip the switch back to the "I" position, and then power on the system. See if you get a display and it will POST and then boot.
 

rawfiul

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POST is the process that happens when your BIOS/CMOS runs through it's hardware checks to initialize all the hardware and make sure it is all running normally and as expected, and make the necessary adjustments if there has been any change to the hardware configuration.

Boot is what happens AFTER the POST process is complete, and entails loading up the necessary files and drivers into memory so that the operating system can run.

In the future, do NOT cut power to the power supply by having it switched and turning that switch off and on each time you want to power up or shut down. It is BAD for the power supply to constantly have it's power cut on and off all the time, even if the system has already shut down. Simply leave power connected to the power supply and just shut down normally using the start menu options in Windows. Once you click shut down, that's it. Leave it alone after that until the next time you come back to it and press the power button to turn it back on. Or, simply put it to sleep using the start menu options each time you are done and then just come back and touch the keyboard or move the mouse. It's faster and uses practically zero power while in sleep state.

Try this.

With the computer shut down and the power cable disconnected from the wall (Or the switch on the back of the PSU flipped to the "0" position)

Completely remove the graphics card from the motherboard. Don't just unplug it from the monitor, take it totally out of the board.

Then, plug your display cable into one of the video outputs on the back of your motherboard.

Plug the power cable back into the power supply (Or flip the switch back to the "I" position, and then power on the system. See if you get a display and it will POST and then boot.
Interesting, i didn't know i shouldn't cut power from wall to PSU after use. Being honest, i still don't fully believe it.

Also, my pc didn't turn on today. Hitting the power button on cabit would make the fans go off but no light in cabinet and no power to peripherals. Send my psu for RMA.
 

Darkbreeze

Retired Mod
There are actually SEVERAL reasons why you shouldn't do it.

For one, every time you cut power to the board the CMOS battery has to take over in order to maintain the system time/clock and BIOS settings. This will cause the CMOS battery to fail or discharge much faster than when left plugged in/connected because even when shut down so long as the switch is still on and it is still plugged in, it continues to feed a very small trickle of power to the board in order to maintain the time and BIOS settings without having to rely solely on the CMOS battery.

For another, the PSU contains capacitors that begin to discharge when power is cut to them. Each time you reconnect power there is some amount of inrush current, and when this is done repetitively on a regular basis, it WILL eventually degrade or destroy those caps.

One of those people I mentioned is Jon Gerow, who is also known as JonnyGuru, and is in fact the head of PSU development and engineering for Corsair's power supply division and was until recently a somewhat active member here as well as having been the founder of the JonnyGuru website which is no longer operational but which was for years one of the main sources of professional in depth power supply reviews on the internet. Here is exactly what he had to say on the subject.

On 5/27/2019 at 7:32 PM, jonnyGURU said:

Repeated in-rush circuit can eventually damage a PSU.

When you "turn off" the PC from the OS, the PSU is still in standby. The bulk cap is still fully charged. When you flip the switch on the back of the PSU or from the wall outlet, +5VSB to the motherboard is cut and the bulk cap slowly discharges. Then, when you turn the power back on, the bulk cap has to fully charge before the PSU can work again. This "rush" of power is called "inrush current". There are things in place to prevent inrush from damaging pretty much every PSU out there, but REPEATED inrush current will eventually shorten the life of the PSU.
And, furthermore, if you are killing the switch because you THINK it might help to protect the system from a lightning strike or similar inrush event, it won't. The only way to protect the system from that is to have a very high quality surge protection unit in place (And if the strike is close enough and severe enough, and especially if your house is not properly well Earthed, it still won't protect it) or completely unplugged from the wall. And you should only feel the need to do that if you know there are storms in the area, not every time you power down.

There are other reasons why a PSU might not power on, such as a faulty Power OK signal from the motherboard, a bad switch on the case, a short circuit somewhere on some piece of hardware that is causing the protections in the PSU to not allow it to turn on, and so on. That being said, I find no fault with an RMA on the power supply aside from maybe having to pay for shipping for no reason if they find nothing wrong with it, but generally we like to do a bit more testing of the component before making that determination.

A bad graphics card, for example, will often cause the PSU to trigger it's protections and not power on, so there should be some process involved but let me know what happens with the RMA and the result. It might just be only the PSU but it seems unlikely since you had this problem before and a new PSU replacement did not solve the problem. But it also might be that the PSU WAS the problem, and that they didn't actually replace it, so you never know unless you take steps to ensure you do not get the same product back like making a small identifying scratch on the bottom of the unit's housing or label so that when you get the replacement you can tell if it's the same unit. They never repair. They always replace if they find it to be bad.
 
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rawfiul

Reputable
Apr 14, 2018
88
0
4,630
0
There are actually SEVERAL reasons why you shouldn't do it.

For one, every time you cut power to the board the CMOS battery has to take over in order to maintain the system time/clock and BIOS settings. This will cause the CMOS battery to fail or discharge much faster than when left plugged in/connected because even when shut down so long as the switch is still on and it is still plugged in, it continues to feed a very small trickle of power to the board in order to maintain the time and BIOS settings without having to rely solely on the CMOS battery.

For another, the PSU contains capacitors that begin to discharge when power is cut to them. Each time you reconnect power there is some amount of inrush current, and when this is done repetitively on a regular basis, it WILL eventually degrade or destroy those caps.

One of those people I mentioned is Jon Gerow, who is also known as JonnyGuru, and is in fact the head of PSU development and engineering for Corsair's power supply division and was until recently a somewhat active member here as well as having been the founder of the JonnyGuru website which is no longer operational but which was for years one of the main sources of professional in depth power supply reviews on the internet. Here is exactly what he had to say on the subject.



And, furthermore, if you are killing the switch because you THINK it might help to protect the system from a lightning strike or similar inrush event, it won't. The only way to protect the system from that is to have a very high quality surge protection unit in place (And if the strike is close enough and severe enough, and especially if your house is not properly well Earthed, it still won't protect it) or completely unplugged from the wall. And you should only feel the need to do that if you know there are storms in the area, not every time you power down.

There are other reasons why a PSU might not power on, such as a faulty Power OK signal from the motherboard, a bad switch on the case, a short circuit somewhere on some piece of hardware that is causing the protections in the PSU to not allow it to turn on, and so on. That being said, I find no fault with an RMA on the power supply aside from maybe having to pay for shipping for no reason if they find nothing wrong with it, but generally we like to do a bit more testing of the component before making that determination.

A bad graphics card, for example, will often cause the PSU to trigger it's protections and not power on, so there should be some process involved but let me know what happens with the RMA and the result. It might just be only the PSU but it seems unlikely since you had this problem before and a new PSU replacement did not solve the problem. But it also might be that the PSU WAS the problem, and that they didn't actually replace it, so you never know unless you take steps to ensure you do not get the same product back like making a small identifying scratch on the bottom of the unit's housing or label so that when you get the replacement you can tell if it's the same unit. They never repair. They always replace if they find it to be bad.
Interesting stuff about psu capacitors.

I took the PSU to the local service point of official corsair so no cost involved there; it was the only component still in warranty.

Even if my mobo or gpu is gone, i cant afford a new one right now 🙃
 

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