Dying CPU/ Mobo?

[BradB111]

Hello all,

 

So this one has been really bugging me despite my experience in PCs, for all those who fancy a challenge perhaps, Not at home at the moment but will provide as much detail as I can.

 

Specs:

CPU - 6700K @ 4.8GHz (completely Stable)

GPUs - 980Ti (2x SLI) (Moderate OC)

RAM - 16GB Dominator Platinum @ 2666Mhz

Mobo - ASUS Z170 Deluxe

PSU - Corsair RM1000i

Cooling -  Custom dual loop hardline loops - 2x 480 EK rads (the really thick ones, the 'XE' series I think?)

              - full cover EK blocks on the GPUs along with the Supremacy Evo for the CPU

 

All items were purchased around their time of release so they are getting on a bit now.

 

So, approximately a year ago I experienced a hard shutdown out of nowhere, everything just immediately lost power, monitors went black (but were still turned on), led strips lost power, fans stopped spinning, everything. Immediately i thought of overheating as it had all the same characteristics except one major factor, there was absolutely no throttling or slowdown of any kind leading up to this loss of power and had been running like this for a good number of years with no issues. I thought little of it, Turned the PC back on, adjusted the fan curves to be a tad more aggressive and continued to monitor temperatures. What was odd is before I adjusted the fan curves I was seeing maybe 60deg C under load which is nowhere close to causing this kind of power loss due to overheating. Anyway, I ignored this and put it down to one of those things we as PC enthusiasts just have to put up with as it continued to operate just fine after this event.

 

I can rule out an unstable overclock as shutdowns aren't usually an instant loss of power and I can also get a stable 4.95 GHz although I'm pushing more voltage than i'm comfortable with 1.48v I think it was. Anyway, that was years ago when the parts were new, backed off the clocks to 4.8GHz and voltage to 1.36V and it has been fine until this.

 

Fast forward 6 months and the same thing happened again this time the PC would not post, I can't remember the error code but I remember it relating to the CPU / RAM, ultimately the fix for that was reducing the tension of the CPU block so there was less pressure on the CPU which was very odd as the EK Supremecy EVO block requires tightening all the way until the thumbscrews bottom out which results in the correct tension on the socket so this means the CPU would only run with less than ideal pressure.This has been happening for the past 6 months maybe once a month where adjusting the pressure would cause it to boot and function normally. However I couldn't post anything in the forums for any advice as I couldn't manually reproduce the issue whatever I did.

 

That is until last night, the PC shut off instantly like it had previously but this time rebooted and refused to post, and nothing I did previously worked and other general troubleshooting steps. The PC would only boot into in a very odd state where nothing except the LED strips and the PSU was powered on (fan spinning). 

 

Things to note: Error code / Q-code '00' (so no error code as such), No error beeps, no power to fans, no power to RAM (No LEDs) 

 

In my experience this is exactly what it can be like when the 4/8 pin CPU power plug is disconnected so out came the multimeter however all 4 positive pins were reading 12V when the PSU was running so that rules out the PSU (unfortunate as that's one of the cheapest components).

 

Things I have tried that Do Not work: Reset CMOS, Unplug USB Devices, Adjusting CPU Block Tension, Reseating RAM.

 

The ONLY thing that seems to solve this now is leaving the PC turned off (at the PSU) for approx 15 mins and then attempting to boot. However, as soon as the PC shuts down (via the normal windows shutdown procedure or otherwise) it will once again be stuck in this state detailed above if I attempt to boot again without doing another 15 min power cycle.

 

In between me being able to actually use my PC I have updated the BIOS also removed all overclocks as an attempt to resolve the issue but no change. Wishful thinking I must admit.

 

If anyone can shed any light on this it would be much appreciated. If any more info is needed I will try my best to provide it. I also plan to video this when I get home so I will post that when I can.

 

Many thanks.

[Jurrunio]

Wait, still 1.48V at 4.8GHz?

[BradB111]

Just now, Jurrunio said:

Wait, still 1.48V at 4.8GHz?

Oh wow, no 1.36V now I will edit to clarify.

[Radium_Angel]

9 minutes ago, BradB111 said:

so that rules out the PSU

Not at all.

It could still not be able to provide the power required for a full post.

Start with a new PS, restore everything back to factory default (no OCing) see what happens

 

[BradB111]

6 minutes ago, Radium_Angel said:

Not at all.

It could still not be able to provide the power required for a full post.

Start with a new PS, restore everything back to factory default (no OCing) see what happens

 

Ahh that's another thing I did try (stock clocks I'll add that too) also a result of a CMOS reset, sorry there's so much info its easy to miss the odd bit I guess. Shame I don't have another PSU to try. so you are saying it may not be able to deliver the full wattage at 12V? Its possible but i find it hard to believe as even after a 6 hour gaming session yesterday after I did get it to post it was seemingly completely fine.

[Radium_Angel]

Just now, BradB111 said:

Ahh that's another thing I did try (stock clocks I'll add that too) sorry there's so much info it easy to miss the odd bit. Shame i dont have another PSU to try. so you are saying it may not be able to deliver the full wattage at 12V? Its possible but i find it hard to believe as even after a 6 hour gaming session yesterday after I did get it to post it was seemingly completely fine.

Sudden shut downs are a clear sign (for non OC'd units, IME) of a failing power supply. Something pulls more power than it can handle and *poof* instant shutdown.

I'd start with the PS first before looking at other failing components.

 

[BradB111]

18 minutes ago, Radium_Angel said:

Sudden shut downs are a clear sign (for non OC'd units, IME) of a failing power supply. Something pulls more power than it can handle and *poof* instant shutdown.

I'd start with the PS first before looking at other failing components.

 

I'll see if I can find one to borrow or rip out of an old system at work, even if its a 350W unbranded and I can get it to boot consistently I guess its a step forward. Its strange how it doesn't explain the first couple of instances of this happening, Block pressure etc... perhaps unrelated?

 

EDIT: @Radium_Angel The PSU is spec'd as having multiple 12V rails, maybe a different socket on the PSU side for the CPU power may be worth a shot?

 

[Radium_Angel]

17 minutes ago, BradB111 said:

EDIT: @Radium_Angel The PSU is spec'd as having multiple 12V rails, maybe a different socket on the PSU side for the CPU power may be worth a shot?

I doubt it, if the master PCU can't supply the full power, then it won't matter which rail you use.

[Radium_Angel]

18 minutes ago, BradB111 said:

Block pressure etc... perhaps unrelated?

I'm not an expert on OCing, except to know it can wear out systems faster, hence why I suggested to put everything back to default and test from there,

Sometimes systems just won't hold the OC for long periods of time, it's stressful...

 

I assume you've checked for physical damage on the board, blown caps, water leaks, etc?

[BradB111]

1 minute ago, Radium_Angel said:

I doubt it, if the master PCU can't supply the full power, then it won't matter which rail you use.

I suppose if all else fails I can try using a 4S Lipo I use for racing quads up to it. I could do with an excuse for an upgrade

[BradB111]

9 minutes ago, Radium_Angel said:

I'm not an expert on OCing, except to know it can wear out systems faster, hence why I suggested to put everything back to default and test from there,

Sometimes systems just won't hold the OC for long periods of time, it's stressful...

 

I assume you've checked for physical damage on the board, blown caps, water leaks, etc?

yeah I get that, but at 4.8 it seems to run happily and still hits the mark you'd expect, I think I got very lucky with my CPU as at the time there was a site selling '4.8GHz validated' 6700Ks at almost double the price, meanwhile I could get 4.9GHz with very little effort, 1.4V I think. Of course to be on the safe side I didn't run at those clocks outside of benchmarks etc..  

 

In regards to physical damage I've checked everything except the socket itself (haven't had the time to drain, dismantle, rebuild etc.. quite yet). (profile pic is my PC) Hard to see how there could be any damage to the socket though considering the CPU has been in it from day 1? Anything's possible I suppose.

[BradB111]

Ok I have another PSU to test when I get home. Will keep you updated.

 

EDIT: @Radium_Angel so, I get home and its working completely fine again, not sure if leaving the PSU power off all day has done the trick? will stress the system then see if it starts happening.

 

[Radium_Angel]

2 hours ago, BradB111 said:

stress the system

Dontcha just love trying to troubleshoot *sometimes* problems?

Always fun!

Good luck, let us know what's going on.

[BradB111]

1 hour ago, Radium_Angel said:

Dontcha just love trying to troubleshoot *sometimes* problems?

Always fun!

Good luck, let us know what's going on.

Ok I'm pretty sure you've hit the nail on the head there @Radium_Angel. Played some MW2 spec ops for an hour, turned the pc off via shutdown and it wouldn't post.

The same half on state I previously described.

Switched the CPU power and 24 pin to run from a unbranded 300W PSU and it posts right away, tried it a few more times and success every time. Switched the CPU power and 24 pin back to the originals and it went back into that half on state again!

 

Just goes to show a fresh brain always helps, thank you so much for you input. I'd never thought about the voltage being flaky or it wasn't able to supply enough amps at 12V but there you go. 

 

Replacement PSU coming tomorrow, downgraded to an RM850x, never used the smart stuff anyway on the RMi series and 850W should still be plenty. A little disappointed I don't have an excuse for a new build though. I'm looking at the 38GL950G Monitor and there is no way my current system will be able to drive that so a rebuild is round the corner anyway.

 

Thanks once again.