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Tom's Hardware > Forum > CPU & Components > Power Supplies, Cases & Mods > [Solved] Computer will not turn back on for awhile after hard shutdown

[Solved] Computer will not turn back on for awhile after hard shutdown

Forum CPU & Components : Power Supplies, Cases & Mods [Solved] Computer will not turn back on for awhile after hard shutdown

Best answer from mickey21.

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My computer has a BFG 800W power supply (I'm also unsure of its efficiency rating, most psu's I see now days are 80 plus certified, however my psu is a few years old)

 

I have a core i7 920 at stock speeds, 4 hard drives in raid 10, and a gtx 560 ti

 

On occasion my computer will blow a 15 amp circuit breaker, after I flip it back and try to turn my computer back on it will "attempt" to turn back on, (after about 1 second it turns back off) after a period of time ranging from 5 minutes to 1 hour, I can turn it back on and everything acts fine.

 

I have since changed my computer over to its own 15 amp circuit, has yet to blow again. However it does not just do this when the circuit breaker trips, it does it for hard shutdowns as well.

 

So, any ideas why my computer will not power up for that window of time after a hard shutdown?

 

I would also like to note that this problem has been VERY intermittent which has made it difficult to troubleshoot.


Message edited by fykins on 10-18-2011 at 06:08:32 AM
Reply to fykins
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Time for a new psu.
I'll guess that your's is overheating and needs alot of time to cool down before it resets.

Reply to davcon

Why would it only do it after a hard shutdown? Not a crash - when I hold the power button down, it never does it after a proper shutdown, it will always start right back up.

 

It NEVER crashes, so then the only way what your saying could be true is if the 2 issues of the breaker tripping and it not turning back on would have to be related, which I somewhat suspect, however I hope to find a better explanation then that.

 

If heat was the only issue it would make me think that there would be no breaker tripping and the computer would just shutdown.

Message quoted 2 times
Message edited by fykins on 10-18-2011 at 06:20:58 AM
Reply to fykins

fykins wrote :

Why would it only do it after a hard shutdown? Not a crash, when I hold the power button down, it never does it after a proper shutdown, it will always start right back up.

It NEVER crashes, so then the only way what your saying could be true is if the 2 issues of the breaker tripping and it not turning back on would have to be related, which I somewhat suspect, however I hope to find a better explanation then that.


"New psu time" mate.

------------------------------ We have not sent down the Quran unto you (O Muhammad SAW) to cause you misery,
Quran 20:2

We send down (stage by stage) in the Qur'an that which is a healing and a mercy. Quran 17:82
Reply to ghnader hsmithot

get new psu or something could blow in your computer

Reply to scout_03

fykins wrote :

Why would it only do it after a hard shutdown? Not a crash - when I hold the power button down, it never does it after a proper shutdown, it will always start right back up.

It NEVER crashes, so then the only way what your saying could be true is if the 2 issues of the breaker tripping and it not turning back on would have to be related, which I somewhat suspect, however I hope to find a better explanation then that.

If heat was the only issue it would make me think that there would be no breaker tripping and the computer would just shutdown.


It's quite simple if the unit overheats it turns off or else it will burn.
I'll bet the unit is damaged due to the instances you've already posted.
That unit was average when first released and is an old group regulated design.
The 12v output is mediocre for an 800W unit.
It has two 80mm internal fans for cooling do they both work?
Because if only one is working it has no hope in hell of cooling the psu.
These guys identified some flaws with that unit.
http://www.hardwaresecrets.com/art [...] view/525/1

Reply to davcon

COOLER MASTER Silent Pro Gold Series RSA00-80GAD3-US 1000W
http://www.newegg.com/Product/Prod [...] 6817171056

 

Well I'm going to order this psu, I know its more than I need, but I'm going to get an upgrade if I'm going to replace the thing at this point.

 

I now am beginning to suspect that the breaker issue is being caused by an arc-fault breaker, I was unaware that it is now code for these to be installed in all commercial buildings.

 

I still believe that heat alone is not causing this issue, but the situation will probably be resolved when I replace it regardless.

 

And yes, the fans are both fine, I even took it apart (void the warranty that BFG never allowed me to sign up for, for some reason haha) bit dirty but nothing popped, burnt, crispy or anything.


Message edited by fykins on 10-18-2011 at 07:46:28 PM
Reply to fykins
Best answer

Very likely the PSU. And likely caused by the circuit tripping it has experienced over its life or contributed to it.

 

When your computer resets the motherboard does a very simple test to confirm all is good to go.

 

When your computer powers up from a cold start it does a more thorough power test to confirm that the PSU is giving proper power levels to the motherboard. This then tells the motherboard to proceed with posting. Your PSU once overused a bit probably has erratic power levels and the motherboard interprets this as a problem and shuts back down. Give it time to cool and the PSU gives more default power levels to the motherboard which then says okay.

 

Though, this can also sometimes be the motherboard as well and I have seen this to be the case. Your motherboard may have sustained damage to the circuitry that tests the power levels and is no longer accurate so the values it reports to the BIOS on testing are not accurate. Keep that in mind.

Message quoted 1 times
Message edited by mickey21 on 10-19-2011 at 03:19:38 AM
------------------------------ Intel Core i7 950@4.56GHZ
12GB RAM
48TB RAID5 Storage
ATI 6970 XFire
Reply to mickey21

mickey21 wrote :

Very likely the PSU. And likely caused by the circuit tripping it has experienced over its life or contributed to it.

 

When your computer resets the motherboard does a very simple test to confirm all is good to go.

 

When your computer powers up from a cold start it does a more thorough power test to confirm that the PSU is giving proper power levels to the motherboard. This then tells the motherboard to proceed with posting. Your PSU once overused a bit probably has erratic power levels and the motherboard interprets this as a problem and shuts back down. Give it time to cool and the PSU gives more default power levels to the motherboard which then says okay.

 

Though, this can also sometimes be the motherboard as well and I have seen this to be the case. Your motherboard may have sustained damage to the circuitry that tests the power levels and is no longer accurate so the values it reports to the BIOS on testing are not accurate. Keep that in mind.

 


Thank you, this is the best theory I've heard yet, although there is no beep code when it attempts to turn on, I could read my manual and see if there should be one. I hope it is not my motherboard, however this problem existed prior to the breaker tripping (power failures of other sorts would cause it), the only difference is my old place did not have arc-fault breakers. So the breaker tripping is not likly what damaged it, however it could have been just a manufacturer defect that degraded over time if it is the PSU. The PSU will arrive within the week hopefully, after that I can do some testing and I'll report back if that fixed it.

 


EDIT:
I think you definitely pointed me in the right direction, after some research I found this:

 

http://en.wikipedia.org/wiki/Power_Good_Signal

 

"Cheaper and/or lower quality power supplies do not follow the ATX specification of a separate monitoring circuit; they instead wire the power good output to one of the 5V lines. This means the processor will never reset given bad power unless the 5V line drops low enough to turn off the trigger, which could be too low for proper operation." -Wikipedia

 

During the time my computer refuses to start my PSU is holding a charge that is "Lieing" to my motherboard/cpu.

 

I have no real evidence of this being the case but it does all add up.

 


EDIT:

 

Replaced power supply, problem has yet to return.


Message edited by fykins on 10-22-2011 at 04:00:09 AM
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