PC Won't Turn On, but USB Ports Have Power

[ZALindsey]

Hi, everyone

I'm having a problem I cannot seem to figure out. Today, my desktop PC would not turn on. When I pressed the power button, nothing at all happened (no lights, no fans, nothing). I noticed, though, that my USB mouse and keyboard were still getting power and were lit up.

I turned everything off, unplugged the system, removed the system from the surge protector, and removed the surge protector from the wall. I hooked everything up again, but it still would not turn on.

I then tried turning the PC on by pressing the power switch on the motherboard itself; but this did not work either.

I then left it alone for about 10 minutes while I did some searching on this site for an answer. Just for the heck of it, I tried the PC again and it worked. It stayed on and worked perfectly fine for about 30 minutes. After I shut the PC down, I tried to turn it on again, but it wouldn't work. I've been trying to get it to come on for about 20 minutes now and cannot get it to boot up again.

So that's where I am now. Stuck.

For what it's worth, here is my build. http://pcpartpicker.com/user/ZALindsey/saved/tdCCmG

Everything was built about three months ago and has been working perfectly until today.

I would really appreciate any help I can get with this. Thanks!

 

[ZALindsey]

For what it's worth, I've done the paperclip test with the power supply and it passed. I am just completely at a loss here and would appreciate any help at all.

 

[ZALindsey]

I just finished breadboarding the PC for a second time and still cannot get it to work. I tried removing all the RAM, as well. Still, no dice. I have a new power supply and a new motherboard on the way. Do you guys have any other ideas in the meantime?

 

[westom]

[

I have a new power supply and a new motherboard on the way. Do you guys have any other ideas in the meantime?

So you choose the second option - shotgunning. Then no reason to post here. Since shotgunning means keep replacing good parts until something works.

Meanwhile, the other optiion means first learning what exists and what is defective before buying, disconnecting, or replacing anything. For example, what determines when a computer can power cycle? A power controller. A power controller will not even let the CPU execute until it decides everything is OK. Unfortunately most who recommend solutions do not even know a power controller exists.

By requesting some instructiions, one minute of labor, and a digital meter, then the reslting numbrs means the fewer who know this stuff can say - without doubt - what is defective. Then you only buy and replace the defective part. No shotgunning. And you actually learn how your computer works.

Your computer could have been defective three months ago when built. Normal is for a defective computer to still boot and execute. As the obvious defect gets worse, then a machine becomes intermittent. Eventually fails. This is also little understood. Many assume if it works, then it must be OK. Same applies to the paper clip test. It can never say anything is good. It can only detect some types of failures.

USB port still has power? Of course. Why is learned only if using a meter with requested instruction. Other alternative is to just keep replacing good parts only on wild speculation - ie shotgunning.

 

[CrazyHeartsz]

Perform these steps: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

 

[ZALindsey]

Perform these steps: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Thanks for your help, but unfortunately, I have already spent a couple of hours going through that list in its entirety. The most perplexing thing is, this build has been running fine for two months. Just all of a sudden, out of the blue, it decided not to turn on anymore. I even swapped the power supply out with a known good one and that did not resolve the issue either.

 

[CrazyHeartsz]

Perform these steps: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Thanks for your help, but unfortunately, I have already spent a couple of hours going through that list in its entirety. The most perplexing thing is, this build has been running fine for two months. Just all of a sudden, out of the blue, it decided not to turn on anymore. I even swapped the power supply out with a known good one and that did not resolve the issue either.

I had this problem with my PC about 4 days ago when I was building it. All I did was remove the motherboard, and add stand-offs to the case before putting the mobo back and re-wire everything.

 

[ZALindsey]

[

I have a new power supply and a new motherboard on the way. Do you guys have any other ideas in the meantime?

So you choose the second option - shotgunning. Then no reason to post here. Since shotgunning means keep replacing good parts until something works.

Meanwhile, the other optiion means first learning what exists and what is defective before buying, disconnecting, or replacing anything. For example, what determines when a computer can power cycle? A power controller. A power controller will not even let the CPU execute until it decides everything is OK. Unfortunately most who recommend solutions do not even know a power controller exists.

By requesting some instructiions, one minute of labor, and a digital meter, then the reslting numbrs means the fewer who know this stuff can say - without doubt - what is defective. Then you only buy and replace the defective part. No shotgunning. And you actually learn how your computer works.

Your computer could have been defective three months ago when built. Normal is for a defective computer to still boot and execute. As the obvious defect gets worse, then a machine becomes intermittent. Eventually fails. This is also little understood. Many assume if it works, then it must be OK. Same applies to the paper clip test. It can never say anything is good. It can only detect some types of failures.

USB port still has power? Of course. Why is learned only if using a meter with requested instruction. Other alternative is to just keep replacing good parts only on wild speculation - ie shotgunning.

I am sorry if my purchasing a power supply and motherboard upset you. I am on this site because I want to learn what is causing this problem, but I am also trying to minimize this PC's downtime. If the replacement motherboard and power supply do not resolve the issue, I will return them. No harm done.

But, anyway, thank you for your help. I used my multimeter to test all of the 24 pin leads and found all of the voltages were within the specifications (12 V, 3 V, 5 V, etc). Still not convinced the power supply was alright, I went ahead and swapped it with my brother's power supply (it is identical to mine), but that did not work either.

So, I am starting to suspect something in the motherboard must have been failing and is now dead. If you have any suggestions that might help me, I would greatly appreciate it.

 

[ZALindsey]

Perform these steps: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems

Thanks for your help, but unfortunately, I have already spent a couple of hours going through that list in its entirety. The most perplexing thing is, this build has been running fine for two months. Just all of a sudden, out of the blue, it decided not to turn on anymore. I even swapped the power supply out with a known good one and that did not resolve the issue either.

I had this problem with my PC about 4 days ago when I was building it. All I did was remove the motherboard, and add stand-offs to the case before putting the mobo back and re-wire everything.

Thanks again. I appreciate your continued help. I have all of the standoffs (10 total) installed in the case correctly in the ATX configuration. I have also ensured there are no extra standoffs in any other positions. I have also built the PC outside of the case using only the CPU, PSU, and GPU, but that did not work either.

For what it's worth, I do have a motherboard speaker installed and it is not giving any beeps. There are literally no lights, no fans spinning, and no beeps.

 

[westom]

Thanks for your help, but unfortunately, I have already spent a couple of hours going through that list in its entirety.

Numbers from one minute with the meter would have answered all those steps except 16 and 17.

Again, the system could have been completely defective even when first built and booted. Only numbers from meter (doing what you did not do) can identify a problem that might even cause infrequent system problems.

How the meter was used does not repost anything useful. Again: requested instructions with one minute of labor. That still tells you nothing until every three digit number is analyzed by others who really know this stuff. Please do not make assumptions as to what was posted or how to use the meter. How to get a useful answer was quite specific. Even where a meter's black lead is connected makes a difference.

For example, having used the meter, then what did the power controller see and what was it doing? That is known if the meter was used properly.

 

[pcgaming98]

I dunno what's with your computer but for the motherboard beeping, no POST code seems to be coming into season. At least for MSI. My board wouldn't post but all was good.

 

[ZALindsey]

After several hours of digging on the web, I found this post on reddit: http://www.reddit.com/r/buildapc/comments/2jrt1b/psarequest_possible_reoccurring_problem_with_the/

It turns out, this is a known problem with many Asrock Z97 Extreme4 boards. The LDO regulator gets extremely hot when the power supply is switched on. I am going to do some more digging and see if I can find a solution.

 

[ZALindsey]

Thanks for your help, but unfortunately, I have already spent a couple of hours going through that list in its entirety.

Numbers from one minute with the meter would have answered all those steps except 16 and 17.

Again, the system could have been completely defective even when first built and booted. Only numbers from meter (doing what you did not do) can identify a problem that might even cause infrequent system problems.

How the meter was used does not repost anything useful. Again: requested instructions with one minute of labor. That still tells you nothing until every three digit number is analyzed by others who really know this stuff. Please do not make assumptions as to what was posted or how to use the meter. How to get a useful answer was quite specific. Even where a meter's black lead is connected makes a difference.

For example, having used the meter, then what did the power controller see and what was it doing? That is known if the meter was used properly.

Why the hostility? I did a bit of digging through your previous posts and learned you have a habit of making enemies with your chastising remarks. I, and most of the users on this site, do not have extensive experience with electronic debugging. Asking me to follow "requested instructions with one minute of labor" is not useful. To what instructions are you referring? As far as I can tell, all you did was lecture me on the fact that most users are not familiar with the function of a power controller. You didn't actually help me figure out how to test the component.

 

[westom]

Why the hostility?

No hostility was posted. But you were angry to learn that you did not know how to use a meter usefully. You replied emotionally rather than learn how you used a meter said little that was useful. Did you even know of a relevant power controller? If not, then why are you so angry?

The point is only technical. Spend much time and money shotgunning. Or get a complete answer using your meter in a manner that is informative and immediate. Best answers come from facts without disconnecting anything. Superior diagnostic procedure means identifying a suspect without even disconnecting one wire. Those are your two choices. Please stop being antagonistic because you did not learn how to use that meter. Either shotgun. Or learn how a meter and one minute of labor creates an answer without so much confusion.

Hours of labor are made unnecessary by requesting instructions and doing one minute of labor with a meter. That should never create emotion. Your choice is simple. Work harder or work smarter. Nothing in that technical reality should create animosity. However your anger implies you would rather argue than learn. Your choice. Learn something new. Or remain hostile.