Seemingly Random Crashes

[SamTheWelshDragon]

Hello! After over 2 weeks of wracking my brains over this issue I have decided it's best to seek the help of you lovely folk. My computer has been suffering random system lockups for a good while now. It all started shortly after my H100i died a pump-grinding death.

 

The symptoms of the crashes are odd to say the least; whatever is displaying on my monitor at the time will lock up entirely and the system will stop responding to all input (this includes the power button) and there has never been a BSOD.
The crashes are extremely peculiar as it even happens in the BIOS on rare occasion! There seems to be no correlation between what tasks I am running and the crashes as they occur just as often while doing nothing at all at the desktop as they do while the system is under heavy load.

 

I have attempted to diagnose the issue with little success. I have tried;

• Running CPU, GPU & RAM stress testing
• Running diagnostics software
• Reviewing the S.M.A.R.T status of my SSD
• Testing each RAM stick individually
• Testing the system with internal graphics only
• Ensuring all thermals of my system components are within their safe limits
• Reseating my CPU, CPU heatsink, GPU, RAM and all PSU power cables
• Tinkering with Windows power plan settings
• Clearing my motherboard CMOS
• Installing Windows onto another drive
• Upgrading (and downgrading) my BIOS, drivers, etc

… And likely other things I’ve forgotten about! None have revealed any errors nor a pattern to the crashes, and so I am left stumped.

 

My system specifications are as follows;
Processor: Intel Core i7-4790K 
Motherboard: ASUS Maximus VII Impact
Memory: Kingston HyperX Fury 2*8GB @ 1866MHz
Graphics: ASUS GTX 970 STRIX
Storage: Samsung 840 EVO 500GB
Power Supply: Corsair AX860i 

 

And the software I am currently running is;
Operating system: Windows 10 Pro 64-bit (Version 1803, build 17134.228)
BIOS: Version 3003 (2015/11/23)

 

Thank you in advance for checking out my post!
 

As I was writing this post I experienced another crash. After a reset my system repeatedly failed to boot (only reaching the BIOS or displaying a blank screen) though it eventually reached Windows after some perseverance

[SamTheWelshDragon]

Lowering my RAM speeds to 1600MHz restored stability to my system. I’d still like to be able to run my memory at 1866MHz, so if anyone has any suggestions I’d be very thankful.

 

EDIT :-

I have discovered the culprit; it was my mobile phone signal. Phone calls or data usage made within a foot of my case will cause a system-wide lockup.