PC won't boot after shutdown

Street · 18 Feb 2017 at 18:15

I've been having a problem with my PC recently where it struggles to boot after shutting down.

It's an i5 4690k, 4x4GB RAM and Gigabyte GA-Z97X-Gaming 3 motherboard.

The issue seemed to start when I changed from the stock cooler to my Megahelems that I had been meaning to put on for ages so I could overclock it.

Once it's booted, it will stay up and will run fine at 4.2GHz and will stress test all night. However, when I shut it down and go to start it up again the fans will spin but the monitor and keyboard lights won't come on. If I then shut it down, remove a stick of RAM, power it on, it will load into the BIOS and say it failed to boot. I can load it at stock or overclocked settings then and it makes no difference, it will boot fine. I can then shut it down again, stick in the other stick of RAM and it'll boot!

It doesn't matter which stick of RAM I remove or the BIOS settings I use, I've tried it at defaults and overclocked, it does the same. I've removed the CPU and checked the pins in the socket to see if I'd damaged any while fitting the new cooler but these all check out OK. The temps are spot on and doesn't even get too hot while stressing.

Any ideas? Does it look like I've somehow borked the CPU fitting the cooler?!

ChroniC · 18 Feb 2017 at 18:58

Hmm
My first thought was one of the ram stick but it's strange that either stick seems to effect it. Could it be an issue with the dual channel setting on the memory, ( I don't know why). Are they all the same sticks? Would it benefit from a bit more voltage?
Only thing I can think would cause that might be the PSU, but seemingly strange that it would work again at all.
I suppose if it's none of them then it must be the Mobo, but again seem strange it would work again at all. Maybe something that is required to boot the ram on startup is a bit ******

Frankly none of this helps you sorry.

Street · 18 Feb 2017 at 23:06

The RAM was my thought at first too, but I can remove any stick to get it working. It's a mix of RAM, all Corsair Vengeance, 2x4GB 2400 and 2x4GB 2133 however it does the same with either set in. I've pushed the CPU voltage and the RAM voltage up a bit to test it and it seemed to make no difference, even at stock speeds.

I'm leaning towards the mobo or CPU, luckily they're both in warranty. Just need to find a way to test them now though. I'll have another play tomorrow and see if there is a setting or something I'm missing.

Habakkuk · 19 Feb 2017 at 13:38

Instead of pulling a RAM stick, can you unplug it from the mains & then power it back up 5 minutes later instead?

Does this manage to boot?

Street · 19 Feb 2017 at 21:02

Nope, that makes absolutely no difference. I left it unplugged all day today and tried it when I got back in, fans span up but no output.

ChroniC · 19 Feb 2017 at 22:13

Fraid the only real way is to take it apart, and put it back together, (maybe don't touch the cpu).
Stick in just the graphic card and one piece of ram, reset the bois and see if it boots, and then go from there one piece at a time. If it doesn't then you need to resit the cpu.

Street · 21 Feb 2017 at 11:29

Well I think it may have been voltage related on the RAM. The voltage kept defaulting to 1.5v and the RAM wanted 1.65v, however even when I set it to 1.65v and it shutdown and failed to boot it defaulted to 1.5v again. I bumped it up to 1.75v and it's been working perfectly, overclocked as well! There goes my excuse to upgrade..

ChroniC · 22 Feb 2017 at 18:46

It's probably because your different ram speeds. Which is something I thought might be the case. You would probably have a more stable system if you swapped out two of them for 4 the same.

Street · 22 Feb 2017 at 22:28

I got one set for free so can't complain, otherwise I'd have got a matched set. I was toying with the idea of selling all four and buying two 8GB sticks. It maybe something to do in the future, or just live with it until I upgrade which will hopefully be later on this year.

I'm actually not sure it was the voltage alone causing the problem in the end, I can replicate the problem if I turn Fast Boot to auto or enabled even with the voltage increase. With it disabled and the RAM voltage at 1.7v it seems rock solid.

Doug2507 · 24 Feb 2017 at 05:16

Mixing different kits of RAM is always a bad idea.

Street · 1 Mar 2017 at 10:37

Well I bit the bullet and just replaced the lot with two 8GB sticks. It all works a lot better now at stock volts and timings! It's weird as it did used to work until I changed the cooler. I'll have to lump the other sticks on the MM.