1 mem slot & 1 PCI-E slot - STOPPED working

[Nicholas Peyton]

Hi guys,

My PC is not in a case. The motherboard sits on top of a large book on the desk.

It worked fine for two years (no problems), then suddenly about a year ago one memory slot stopped working. (I only have two slots -- with 8GB in each for 16GB total).

Then shortly after one of my PCI-E x16 slots also stopped working -- not exactly the same time as the RAM slot stopped working but close. I also remember that before the GPU stopped showing completely it was only running in x2 mode (I think). -- I haven't tried moving the GPU to another slot because the system is water-cooled and there's an industrial water chiller in my loop so draining it all then cutting longer tubing etc ---- well, suffice to say it would be a timely undertaking.

I tried drastically underclocked my CPU (by more than 1Ghz) and the memory slot started working again. I also remember this originally started off as an intermittent problem. When I returned my CPU clock to normal the slot needed to be disabled before the PC would boot again.

Originally the book underneath my mobo supported it from the edge of the right-hand side of the board up to the start of the right-hand side of the CPU socket. (So the area left of the CPU socket was unsupported. But I don't have a heavy cooler on the CPU. Only an EK water block. (There is however an on-switch on the motherboard itself in the top left-hand corner of the mobo which I press to turn the PC on). Since the issues with memory and PCI-E, I replaced the book with a larger one that supports the entire motherboard from corner to corner.

It IS worth noting however though -- that my motherboard is the ASUS IX APEX. A motherboard designed for LN2 benching. (ASUS claims it's been through all kinds of physical drop/warping tests which would seem to rule out the fact that me simply pushing the power button on the previously unsupported corner would have been enough to bend/damage the board). It never looked bent - not even slightly; (before I swapped in the fully supportive book).

I did also notice, (again before I swapped in the bigger book), that the power-on button on the motherboard needed to be pushed down with a tiny bit more pressure for the button to function (and the PC switch on). Since the bigger book supporting the entire bottom of the mobo was swapped in the button requires no pressure at all. (Don't know how relevant this is to the issue I'm having but thought I should mention absolutely everything).

Any ideas? Thanks.

This is my first time on here in over two years -- I used to be very active but nearly closed my account in 2018 due to over-the-top politically righteous moderators who seemed to enjoy justifying themselves. (In other words, a community that I once loved changed into something that got so petty about unimportant matters it ruined the atmosphere. I hope things are back to normal. This is my first post where I suppose I am testing the water!

Any way many thanks in advance for reading my main post (slot problems).



~Nick Peyton


My rig
Intel 7700k
ASUS IX Apex
2X8GB DDR4 G-Skill 3600
GTX 1080Ti

Full custom water loop:
-Using an industrial water-chiller instead of a radiator.

 

[Valantar]

Since you're using a chiller I assume you've been running sub-ambient fluid temperatures. That immediately makes condensation (and thus corrosion) the most likely culprit. I would remove the CPU from the socket and check its pads and the socket pins for corrosion and discoloration. Giving the socket a soak in isopropyl alcohol (or some electronic contact cleaner that doesn't leave residue) might be a good idea too. Simultaneous failure of both a RAM slot and a PCIe slot makes me think the issue is with the socket or CPU itself and not the board, as those traces would be in quite different areas for the most part, making it unlikely for bending to simultaneously cause stress failures in both. Mounting pressure is another possible culprit, but nothing in your post makes me think that would have changed recently.

 

[WhitetailAni]

It sounds like your CPU is loose. If all the pins aren't contacting, you won't get full functionality (much like how Threadripper users can experience dead memory channels if their CPU is seated incorrectly)

 

[erocker]

It sounds like your CPU is loose. If all the pins aren't contacting, you won't get full functionality (much like how Threadripper users can experience dead memory channels if their CPU is seated incorrectly)

I think that would be the case if the CPU was freshly installed, but it isn't. With the water chiller, I'm thinking there's a few corroded pins that happened during operation.

 

[Caring1]

I'm more likely to blame heating/ cooling cycles and board flex for cracked traces.

 

[Nicholas Peyton]

That's brilliant guys.

Thanks for all your replies.

I'll remove the block tonight and try reseating the CPU, (plus socket cleaning, if there's corrosion).

It is important to note though - that it's been years since I have ran the chiller at below ambient. Plus whenever no did in the past I always used a "dew point meter" to ensure i wasn't going low enough for condensation to form.
On the other hand though I did have an accident once where I forgot to raise the thermostat and had a condensation fright. (The PC was immediately switched off and left to dry out before also doing a run with the coolant at 40-50c for a while as an extra safeguard).

Anyway thanks again I'll try the reseat tonight.

Sincerely,
Nick.

P.s. nearly forgot. My CPU is delidded and the IHS wasn't glued back on. The pressure of the block holds it in place. Don't know if that would of contributed to the issue.

 

[MentalAcetylide]

the system is water-cooled and there's an industrial water chiller in my loop

I'm not sure if its applicable, but there's also the coefficient of expansion, which varies between material types. Too much of a temperature difference/fluctuation between different materials packed snugly together can cause problems over time. For an extreme example, this is how water is able to literally destroy cement & stone buildings via repeat cycles of freezing & thawing. I would imagine electronics are more sensitive compared to cement/stone.

I wouldn't use something like that unless I was able to have the case hermetically sealed in its own environment with the moisture-containing air completely replaced with a non-reactive gas.