PC Will not Post after Overclock

[uwpsci204]

I have an i7 6700k on a Gigabyte Z170X UD3 Ulta motherboard. I also have a corsair h100i. I built my PC nearly two years ago and had no issues until yesterday. 

 

I initially overclocked my machine to 4.5GHz when I first built it. I initially thought it was stable, but I realized yesterday that it might not be as stable as I thought. I ran Prime95 and I got a BSoD a few minutes in. Upon reboot I went into the bios, and enabled the XMP Profile as well as upping my voltage from 1.375 to 1.4V as a test. I rebooted the computer and it failed to post. When the computer tries to boot, it powers on, all the lights in the pc come on, and then it restarts a few seconds later. 

 

I thought that this would be a simple case of resetting the cmos, so I powered off the computer, unplugged it, flicked the PSU switch and held a screwdriver over the reset cmos pins for a few seconds (as described in the motherboard manual). Plugged everything back in, and no luck. Then, I tried removing the cmos batter for about 30 seconds and plugging it back in. Unfortunately, that did not work either. Then, I took out my ram and tried every individual stick, in every individual slot to see if it would post. No luck there either. I then stripped down the computer to only the motherboard, cpu, cooler and one stick of ram. That did not work either.

 

Then, I took out the cmos battery last night, left it out overnight and put it back in this morning. I left the power cable out and held down the power button for 30 seconds to discharge the capacitors. I tried to boot again with no luck. The lights on my motherboard and graphics cards turn on as usual, but my keyboard and mouse lights do not (I'm not sure if they are supposed to be on before post). 

 

I'm not sure what to try next. If a component is fried, what is it most likely to be? Motherboard, cpu, ram, psu? Is there anything else I can try to get my computer to boot? 

 

EDIT: When trying to post, the computer will continuously restart. The lights will come on, fans will spin, and a few seconds later, the computer will restart and the process keeps repeating.

Edited August 12, 2018 by uwpsci204
More details

[Crunchy Dragon]

What PSU?

 

I've had multiple instances where a PSU will be unable to supply enough power to actually power on a system, but fans and LEDs will turn on. Nothing else will work, not even peripherals. Sounds a lot like the problem you're having.

 

If the CPU or motherboard was dead, you'd hear a click from the PSU and the fans wouldn't spin for more than a couple seconds.

[uwpsci204]

Its a Corsair CS650M. I have a GTX 1070 in there as well. When I try to boot, the fans spin for a few seconds, but stop spinning when the computer reboots itself. @Crunchy Dragon

[Opencircuit74]

That motherboard has a dual-BIOS config on it. See if you can change the BIOS, there should be a switch or something.

[uwpsci204]

22 minutes ago, Opencircuit74 said:

That motherboard has a dual-BIOS config on it. See if you can change the BIOS, there should be a switch or something.

I looked through the motherboard manual and there is no mention of a switch to change the bios. I found the following instructions online however. 

 

Quote

1. Shut off the power supply using the switch on the back of the PSU, wait 10-15 seconds.
2. Press and hold the case Power On swtich, then while still holding turn on the power supply from the switch on the rear.
3. Still holding the case power on switch, the board will start, once it does release the case power on switch and shut off the power supply via the switch on the read of the unit. (Do the latter two parts as quickly as you can once the board starts)
4. The board will shut down.
5. Turn the power supply back on using the switch on the rear of the unit.
6. Turn on the motherboard by pressing the case power on button.

Once the board starts this time you should see the Gigabyte splash screen, or POST page, then the Auto-Recovery from Dual BIOS will kick in. You will see a checksum error, and then recovery from BACKUP BIOS will begin. Once it is done reboot your machine and enter the BIOS and load optimized defaults then save/apply/reboot back to BIOS. 

 

This did not work either, I never got a post screen. The computer just keeps restarting itself. 

[uwpsci204]

2 hours ago, Crunchy Dragon said:

What PSU?

 

I've had multiple instances where a PSU will be unable to supply enough power to actually power on a system, but fans and LEDs will turn on. Nothing else will work, not even peripherals. Sounds a lot like the problem you're having.

 

If the CPU or motherboard was dead, you'd hear a click from the PSU and the fans wouldn't spin for more than a couple seconds.

So a bit of an update. I went to my moms and got the PC I built for her. I took out her power supply (Corsair CS500) and used it to power my computer. It still does not post. I have noticed that the motherboard LEDs come on, and all of my case fans start. However, a few seconds into the process, one of my H100i case fans stops running. The other two case fans keep running throughout. 

 

If this rules out the PSU, then would it most likely be the motherboard causing the issue? Could it be the ram? 

[NeoAthlon]

Any chance you have post leds, or a post code readout on that motherboard, typically located near the ram slots if it has it. When you power on a post led will cycle through colors as it test the cpu/ram/gpu.  If not, do you see anything at all displayed on the screen, 2 digit hex code, usually found in the top left or bottom right corner will provide post codes that could let you know what's going on.  If none of the above, see if you can find a motherboard speaker(assuming you don't have one already, most modern builds don't), this will give you an audible post code.

 

Have you tried pulling it out of the case and doing a test with it sitting on a non conductive surface(cardboard is cheap and works), just motherboard, cpu, and ram, no gpu or sata/m.2 drives plugged in.

 

Just for a quick power on test, you don't even need your cooler attached, if it hits tj max it'll throttle, but at stock speeds(which you should get after resetting cmos) you have a few minutes in bios before it gets anywhere near that hot(you can hold a finger on the ihs to "monitor" the cpu temp while doing this and power off when you feel like it's too hot.)

 

 

[DarkSmith2]

sometimes you have to get the battery out for longer than 30seconds. Try 30minutes.

[uwpsci204]

20 minutes ago, NeoAthlon said:

Any chance you have post leds, or a post code readout on that motherboard, typically located near the ram slots if it has it. When you power on a post led will cycle through colors as it test the cpu/ram/gpu.  If not, do you see anything at all displayed on the screen, 2 digit hex code, usually found in the top left or bottom right corner will provide post codes that could let you know what's going on.  If none of the above, see if you can find a motherboard speaker(assuming you don't have one already, most modern builds don't), this will give you an audible post code.

 

Have you tried pulling it out of the case and doing a test with it sitting on a non conductive surface(cardboard is cheap and works), just motherboard, cpu, and ram, no gpu or sata/m.2 drives plugged in.

I don’t have post leds or a motherboard speaker, and no codes come up on the screen. 

 

I also tried just the motherboard, psi, ram and cpu on my motherboard box. That didn’t work either. 

 

I went ahead head and ordered new components. Do you know what could have caused this issue though? I didn’t think I would have had any negative results by enabling XMP and setting voltage to 1.4. I want to make sure it doesn’t happen again. 

[NeoAthlon]

I don't know without looking what's considered a "safe voltage" for 24/7 overclock on that cpu, but I don't think that what you were running would have been an issue(unless the board was actually running higher than the voltage set in bios).  2 years seems like a pretty short life cycle in my experience even with an overclock, and yours wasn't crazy high or anything. 

 

It's probably safe to say your cpu is fine, if your overclock ran fine for 2 years, then suddenly started showing signs of instability, my guess is you have caps or vrms on your motherboard that ran hot for awhile, and have prematurely reached the end of their life cycle. One side effect of using most aftermarket coolers(especially an aio) that is typically not thought about, is your removing direct airflow from the components surrounding the cpu socket(vrm and caps).  If you can manage to find someone with a compatible motherboard to test your cpu in that seems like the next logical step. 

 

If you can't find a board to test it in, you may have to resort to a place that does pc repair or deals in used hardware.  Talk to the workers, explain what you're dealing with, maybe you can get lucky and they'll have a 6th/7th gen intel system on a workbench they would willingly toss your cpu in and give it a power on test. It'll take em 10 minutes to do it and you can toss em $20 or so for their trouble rather than the 1 hour minimum charge most places have.

 

 

While your there see if they have a post speaker, should be like, a dollarish, and handy to have around in cases like this, might also help you to see if your motherboard is producing any post codes before you ask them to test your cpu for you.

Edited August 12, 2018 by NeoAthlon
pic - post speaker