Asus X99-A Ram slots suddenly stopped working

comeradealexi · 31 Aug 2022 at 19:10

Hey all. Something bizarre happened today where my PC wouldn't even get to bios boot screen, just stayed black. Eventually after many reboots I got into Windows and noticed half my RAM was missing (Showing 8gb instead of 16gb).

Rebooting it got stuck again and I started using the MemOk! button and it kept rejecting the ram sticks in the 4 slots on the left of the CPU. (A1, A2, B1 B2).

I've tested all sticks together and individually on all slots on the right side of the motherboard (C1, C2, D1, D2) and it works correctly. Testing any stick in any combination or individually on the left hand slots just will not work at all. I've reset the bios entirely multiple times as well.

So it doesn't seem like the RAM is busted, just the 4 slots on the left hand side of the motherboard... I've never had this happen before but I was wondering if there is anything I can do? I'm not benefiting from Dual/Quad channel as a result.

My motherboard, RAM, CPU combination hasn't changed or been touched since I first installed it back in 2015 but just today it's suddenly gone pop!

Does anyone have any ideas about what I can do? Or does it look like I need a new motherboard?

Any help would be greatly appreciated!

Motherboard: Asus X99-A (rev 1)
RAM: Kingston Predator 16GB (4x4GB) DDR4 PC4-24000C15 3000MHz Quad Channel Kit - Black (HX430C15PB2K4/16)
CPU: Intel 5820K 3.30GHz (Haswell-E) Socket LGA2011-V3 Processor - Retail (BX80648I75820K)
GPU: GTX 1070

tamzzy · 31 Aug 2022 at 19:32

either one of the mobo transistors have popped or the cpu's IMC has gone

comeradealexi · 1 Sep 2022 at 21:05

tamzzy said:
either one of the mobo transistors have popped or the cpu's IMC has gone

Thanks Tamzzy. This is what I was fearing! Thanks for your help!

Conor Royston · 7 Sep 2022 at 19:29

Just wanted to add here, as I have the exact same board, and Me and OC themselves have had problems with it after sending it in. C1 slot for me has been playing up for most of 3+ years. I dare say my problem is even weirder than yours.
Nothing has blown, no bent pins, ran hours upon hours of tests of every combination of RAM stick and a 2nd and 3nd borrowed lot. (I'm guessing OC did all these tests as well themselves)
C1 slot will randomly either show in bios as 24/32GB but when actually on windows it'll show 32/32, or it'll show in BIOS 32/32GB yet in windows shows 24/32 xD

OC couldn't figure out the problem fix and I've recently I've started getting many more blue screens, errors, - windows doesn't shut down if I go through start menu shutdown, (gotta do alt/ctrl/delete and wait 10 mins for it to shut down or force through power switch), also my general loading up of the PC does disc checking every turn on (zero errors always) and if I want to open up folders on any hard-drive/SSD or M.2 just opening them up to load the files inside on a tiny folder can take 5 minutes alone.

I've just decided to wait for the new AMD CPU/motherboards being released this month and go all out on an upgrade, replacing and upgrading CPU/Motherboard/Cooler and RAM. Too long with unfixable problems

/rant over hahaha!

Meddling-Monk · 13 Sep 2022 at 00:45

I don't have the x99 chipset motherboard, but I did have the x79 Asus Rampage 4 Extreme (until very recently), the predecesor of the motherboards in this thread. Funnily enough, it too was the "memory" that experienced issues. A few years back, it was discovered a set of my RAM was faulty, or had become faulty (no direct way to really know as the system always had a slight amount of instability, and it was found to be with the VRM settings and the cooling on the VRM as well eventually) got those replaced (for free by Corsair) and all was fine again. Then last year the BIOS and RAM had issues until I re-flashed the BIOS, reset the CMOS and replaced the BIOS battery. All seemed fine again. Until recently, when the boot and RAM issue came up again. Trying the RAM found no issues, and swapping the CPU with a replacement (from 4930k to a 3820k that was known to work) yielded no improvement. Attempting BIOS re-flash, CMOS reset, nothing helped to get the system to boot past the memory boot stage. Suggesting that something on the motherboard itself is what had developed a fault (something on CPU socket, RAM slots, or the motherboard iself). So, like others here, there was no visible fault with anything on the board to diagnose and fix.

Also in the process of hunting down a new setup at this time. And may avoid Asus motherboards, or at least any Intel Asus motherboards. Although, there was known "complications" with both the x79 and the x99 chipsets which helped many others jump ship earlier, so it could just be an inherent issue with those chipsets only as well. In any event, there's nothing to be done at this stage other than a new system for anyone with the same issues as OP and out of warranty.