[SOLVED] Computer doesnt start after hard shutdown. Starts after few hours or a day.

[cerebros]

Hello everyone,
I have a rather unique problem. I have tried look for answers but couldn't find any.
When I'm using my computer and then if I shut it down and start it again . Sometimes it wont start. I have to wait for sometime before I hit the power button and it starts. During that time if I hit the power button it does nothing . There is a green light on the mobo. This has happened multiple times and I'm not sure what is causing it. My initial guess was some sort of surge protection. I have tried removing every component and resetting graphics card and ram and even removing cmos battery.
It dint run after doing all that but magically after a day of just sitting there it started running. The only thing I haven't changes is the power supply.
Any help would be greatly appreciated.
Thanks so much everyone.

 

[bmockeg]

What’s your power supply? How old is it?

 

[cerebros]

What’s your power supply? How old is it?

Ax850 .corsair . I would say roughly 3 or 4yrs

 

[LinuxDevice]

The back of the power supply will have a switch which is not normally used. If you turn that switch off, hold the power button down for about 10 seconds, turn the switch back on, and then try to boot, does it work?

How old is the CMOS battery on the motherboard?

 

[cerebros]

O

The back of the power supply will have a switch which is not normally used. If you turn that switch off, hold the power button down for about 10 seconds, turn the switch back on, and then try to boot, does it work?

How old is the CMOS battery on the motherboard?

Yea. I unplugged all wires. Turned of the button at the back of psu . Held power button for 20 sec. Plugged everything back in and tried again. No luck. I replaced cmos from an existing working PC and tried it as well. It's like the pc has a mind of it's own. It's happened before and if I leave it for a day it works fine. Just annoying..

 

[LinuxDevice]

O

Yea. I unplugged all wires. Turned of the button at the back of psu . Held power button for 20 sec. Plugged everything back in and tried again. No luck. I replaced cmos from an existing working PC and tried it as well. It's like the pc has a mind of it's own. It's happened before and if I leave it for a day it works fine. Just annoying..

Are you able to get into the CMOS and use whatever feature it has for resetting BIOS to defaults? Sometimes if CMOS is marginal (due to power, and the battery is part of power), then resetting to defaults (even if it is already default) can help. If you have anything custom you might poke around and take note before setting to defaults.

 

[cerebros]

Are you able to get into the CMOS and use whatever feature it has for resetting BIOS to defaults? Sometimes if CMOS is marginal (due to power, and the battery is part of power), then resetting to defaults (even if it is already default) can help. If you have anything custom you might poke around and take note before setting to defaults.

Unfortunately it wont start as of now. I meant I replaced the battery. I'm just waiting for it to take it's time as of now. I'm just curious as to why this would happen.

 

[LinuxDevice]

Unfortunately it wont start as of now. I meant I replaced the battery. I'm just waiting for it to take it's time as of now. I'm just curious as to why this would happen.

When it doesn't boot, does it at least get to where BIOS setup can be reached? Like the other poster I suspect it is power related, but I'm trying to zero in on something more specific. FYI, I have had this happen both for CMOS reasons and for an otherwise working power supply which was slightly off spec after 10 years of use.

EDIT: After replacing any battery you'd probably want to run a CMOS reset anyway.

 

[cerebros]

When it doesn't boot, does it at least get to where BIOS setup can be reached? Like the other poster I suspect it is power related, but I'm trying to zero in on something more specific. FYI, I have had this happen both for CMOS reasons and for an otherwise working power supply which was slightly off spec after 10 years of use.

EDIT: After replacing any battery you'd probably want to run a CMOS reset anyway.

If it doesnt boot that doesnt start all. Hitting the power button does nothing as far as I know. There is green led on the mobo which turns on when I plug the power back in but other than that nothing.

 

[LinuxDevice]

If it doesnt boot that doesnt start all. Hitting the power button does nothing as far as I know. There is green led on the mobo which turns on when I plug the power back in but other than that nothing.

Something could be consuming more power than the supply can provide, e.g., a shorted component plugged in. Or the mobo may have gone bad (e.g., bulging capacitors). Or the power supply might be marginal after all that time (this is my bet as most likely).

Sometimes heat will shut things down, but it is occurring too fast to be that, and the times when it does work probably rules that out. If there is any way you can get another power supply to test (one of sufficient power), then that is what I'd do next.

Btw, the motherboard is designed to not turn on until power is stable (in part because of the way power supplies are designed for computers and do not regulate well until there is at least a partial load). It wouldn't matter why the power is not stable, and the time over which it has to be stable is extremely short (nothing you could measure with the average multimeter). Since you've reset the CMOS and sometimes it works (nothing has burned to a crisp) odds are that it is power related.

Almost forgot: Do see if it boots better if no devices are attached to USB.

 

[cerebros]

Something could be consuming more power than the supply can provide, e.g., a shorted component plugged in. Or the mobo may have gone bad (e.g., bulging capacitors). Or the power supply might be marginal after all that time (this is my bet as most likely).

Sometimes heat will shut things down, but it is occurring too fast to be that, and the times when it does work probably rules that out. If there is any way you can get another power supply to test (one of sufficient power), then that is what I'd do next.

Btw, the motherboard is designed to not turn on until power is stable (in part because of the way power supplies are designed for computers and do not regulate well until there is at least a partial load). It wouldn't matter why the power is not stable, and the time over which it has to be stable is extremely short (nothing you could measure with the average multimeter). Since you've reset the CMOS and sometimes it works (nothing has burned to a crisp) odds are that it is power related.

Almost forgot: Do see if it boots better if no devices are attached to USB.

So its finally started now. Is there something I should check before trying to get a new power supply.
Also unrelated to the starting g up issue. I currently have 8 GB ram . 2 identical sticks of 4gb each. I bought 2 more identical sticks of 8gb each. Whenever I plug them in it gives me bsod with stop code memory management. I know for a fact that those ram sticks work fine. Do you think it is the motherboard.

 

[LinuxDevice]

So its finally started now. Is there something I should check before trying to get a new power supply.
Also unrelated to the starting g up issue. I currently have 8 GB ram . 2 identical sticks of 4gb each. I bought 2 more identical sticks of 8gb each. Whenever I plug them in it gives me bsod with stop code memory management. I know for a fact that those ram sticks work fine. Do you think it is the motherboard.

Having bad RAM could easily cause BSOD. I doubt it would prevent POST, but if the RAM were bad enough, then I suppose it could cause the power rail the RAM uses to drop too much. So maybe. There isn't a lot you can tell from a system which boots, but when it fails, try a single stick of RAM.

Do note that if you add RAM, and the RAM is good, but the RAM timing is off from what is already there, then BSOD would likely occur just as if it were bad RAM. You don't want to add that extra pair of RAM unless the timings match.

 

[cerebros]

Having bad RAM could easily cause BSOD. I doubt it would prevent POST, but if the RAM were bad enough, then I suppose it could cause the power rail the RAM uses to drop too much. So maybe. There isn't a lot you can tell from a system which boots, but when it fails, try a single stick of RAM.

Do note that if you add RAM, and the RAM is good, but the RAM timing is off from what is already there, then BSOD would likely occur just as if it were bad RAM. You don't want to add that extra pair of RAM unless the timings match.

I see. what if i just add the 2 newer rams as they are both 8gb stick each compared to the ones that are already installed which are a total of 8gb.
It seems to give the bsod in that case as well. It will start windows , reach the dekstop and then go to bsod screen.

 

[LinuxDevice]

I see. what if i just add the 2 newer rams as they are both 8gb stick each compared to the ones that are already installed which are a total of 8gb.
It seems to give the bsod in that case as well. It will start windows , reach the dekstop and then go to bsod screen.

You really should try them all one at a time and see if one by itself fails. This is bad RAM. As soon as you use two at once you are in the territory of perhaps RAM timing mismatches are at fault. If two at the same time have matched timing, and it fails, then perhaps they just are not closely enough matched. However, if it is just timing between two different sticks of RAM, I doubt this would cause a failure to POST. Do try one at a time on each when boot fails. Then try pairs. Then try two pairs.

 

[something-longrandomstr]

Had the same problem. Turned out that the computer would boot without issue when my (powered) USB hub was off or unplugged.

 

[Parth73]

Had the same problem. Turned out that the computer would boot without issue when my (powered) USB hub was off or unplugged.

Good Shout, i had the same issue with no sign of life after a shutdown. after reading your post i unplugged the power from my USB hub and it fired up no problems. ( made an account to thank you )