Pc Shut Down And Won't Reboot. Tried Everything?

Recently rebuilt with an i7-7700k in an ASUS Z270H mobo. During a fairly long session with the Oculus Rift, my PC just shut down. When I tried to reboot, everything looked good but my monitor never got past HDMI (no signal) then went into standby and black screen. I opened the case and there was definite overheating somewhere, my guess being the GPU (EVGA 1070sc) which smelled nice and burnt.

I gave it a couple hours to cool off and tried again with the same results. Noticed that the LED logo on my H100i v2 pump wasn't lit. I removed the GPU and tried the on board GPU. No good. I checked all my mobo and PSU connections, all good. Reset CMOS, no good. Tried with one stick of RAM,then the other. Still same result. Hooked up an old monitor and still nothing.

I'm at a loss. Everything is powering up - case lighting is good,mobo LEDs are normal, CPU cooler fans and case fans are all blowing and the 1070's lighting is good. The GPU fans aren't moving but it's a first run EVGA with the old firmware and the fns barely ran under normal conditions. The only concern I have is the Corsair logo not lighting up on the pump.

Whatever this is is out of my league, anyone have any ideas before I bring it to a shop? Thanks in advance...

i7-7700k (no oc)
Corsair h100i v2 cooler
16GB Corsair Vengeance @ 3000mhz
ASUS Z270H mobo
Win10 Hom 64-bit
Samsung EVO 500GB ssd
EVGA 1070sc 8GB
Corsair rmx750 gold psu

EDIT: Outside of the factory overclock on the GPU, I was running everything at stock speeds.

 

I would scrounge up a borrowed/spare power supply and see what happens.

 

Pull everything from the mobo except CPU and needed power & power switch and boot - does it POST?
Unplug the power cable and hold the power button for a few then plug it back in and try to power on, POST?

 

Nope. To both. CPU, then?

 

Ummm, if you pull "everything" from an ATX Form Factor compliant motherboard except power connectors and CPU, it will not POST because there's no RAM and no keyboard.

This does nothing on a PC. Some notebooks it works, but this is an old wife's tale option carried over from 25 years ago from the old "AT" Form Factor when the power button connected via a wiring harness directly back to power supply. Today, the power button is just a remote switch to the +5Vsb standby voltage on the motherboard.

So again, you need to try a spare PSU.

 

Seeing there is no logo light on the pump, she would be my main suspect also, especially after an overheat shutdown.
Will she boot using an Air Cooler?

If all the bells n whistles are still running the PSU should be fine, so the easiest way to test (assuming you can boot with an AC) would be attach the pump to an MB header or directly to the PSU, and monitor pump speed (if any) through Corsair link.

http://www.majorgeeks.com/files/details/corsair_link.html

 

Except bells and whistles tend to use +12V. Other devices require +5 or +3.3V. So lights can flash, motors can spin, but that does not mean the other voltages are present. And some devices can easily tolerate voltages that are not within the ATX Form Factor allowed ±5% tolerance while other devices are much more sensitive. And some devices can tolerate an excessive amount of ripple while others cannot.

Considering EVERYTHING inside the computer case depends on good, clean, stable power, it is standard troubleshooting procedure to start at the wall.

Is it plugged in?
Is it turned on?
Is the power supply outputting good, clean, stable and within tolerances voltages?​

No technician worth his salt assumes the power is good without verifying - this is especially true before assuming something else is wrong that requires spending money!

At the very least, you should check your voltages with a hardware monitor program. While in no way conclusive, they are much better than assuming all is good. I recommend using HWiNFO64. Be sure to click the Sensors button.

If it turns out your power supply is working perfectly, great! But it is not great to spend good money on replacement RAM, graphics cards or other expensive components only to discover later you still have the same problems because your power supply was faulty.

 

All good points Digerati, you may well be right!
It was just my guess that she aint booting because the BIOS does not recognize any CPU cooling available due to a faulty cooling pump.....I would test this first by swapping it out with an air cooler to see if that will fire her up. (pardon the pun)

 

I am NOT saying the PSU is bad. I am saying proper troubleshooting requires making sure devices that require power are getting the power they require first. Then there is no guessing needed.

 

But it will should POST an error & give you someplace to start, that is what it is there for.. And draining the system helped a desktop I had an issue with.. so it does do something. I would get a power supply tester, it's cheaper than another power supply. How do you test a power supply on a system that is not booting with a piece of software?

 

But POST would halt the boot process with a RAM or keyboard error. I agree, however, that if you got that far, it would be an indication the PSU is providing some power.

Sorry, but no, it really doesn't.

What likely happened is simple time elapsed - not the process of holding the button. When looking at the circuit the power button connects to, for one, it only connects to the +5Vsb circuit which is isolated from the other main +12V, +5V and +3.3VDC voltages. And second, there are no storage capacitors in that circuit that would discharge from such "bleeding" actions.

Testers are nice, and I keep one of these PSU testers in my tool bag in my truck for house calls. The problem is, they are not conclusive. They only provide one little "dummy load", not a variety of "realistic" loads. And they don't test for ripple and other anomalies that affect computer stability. This must be done by a qualified technician using an oscilloscope or power supply analyzer - sophisticated (and expensive!) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronics repair facilities.

That leaves swapping in another known good PSU as the only option for "normal" users. And of course, for testing purposes, "borrowing" a spare from another computer and/or trusting friend is cheaper than buying another PSU.

Oops! Good point. Perhaps by swapping it into another computer?

 

If it doesn't then why with the AC cable removed, will the fans spin / jump when you push the power button in? Magic smoke make that happen I guess?? Like I said it happened to a board I had, you could see the light on the mobo would stay on for a while, unless you did the drain thing, but I am wrong about my own experience.

 

For a while, but not indefinitely. I am just saying there are no storage caps in that circuit that need bleeding. If you want to ensure there are no residual voltages anywhere, pull the power plug from the wall for 10 - 15 seconds or, if your power supply has one, flip the master power switch on the back of the PSU to off (0).