Question [Solved] PC refuses to POST with 4 sticks of RAM despite working fine for 6 months.

[Zebidiah]

Hi all,

I've been running 4 sticks of Corsair Vengeance RGB 8GB 3200Hz RAM on my Z390 Pro for about 6 months without any issues whatsoever. No crashes, no bugs , nothing.

Today I go to turn on my PC and it refuses to POST. The little diag light indicates a RAM issue, so I try booting with only 2 sticks. This works fine. I then try every pair in every appropriate slot combo, and all of it seems to work fine. Except for the full 4 stick dual channel configuration.

I have the latest BIOS, f12l (It was version f11 when it failed. I updated in an attempt to fix). I tried enabling XMP, that didn't change anything. Wondering if anyone has experienced this before or has any ideas on what to test. All of these parts are about 6 months old.

i7 9700k CPU
Z390 Pro Motherboard
Corsair Vengeance RGB 8GB x4 RAM
EVGA 650 GA PSU
EVGA 2070S GPU

SOLVED: Turns out one of my sticks of RAM went bad. Found this out by look at the SPD Info of each DIMMS and seeing that one had a totally faulty module capacity reading. Picture of the info below. Tried booting on just that stick and it failed to POST.

 

[SamirD]

Sounds like either the memory or board went bad just enough to cause this issue.

 

[Zebidiah]

Sounds like either the memory or board went bad just enough to cause this issue.

That is unfortunately what I am beginning to believe. Just tried upping the voltage on the RAM, that did not work. Also loosened the AIO a bit as I've seen suggested, that didn't work. I am just hoping its not an issue with the CPU. Would rather it be the motherboard or the RAM.

 

[Third-Eye]

That is unfortunately what I am beginning to believe. Just tried upping the voltage on the RAM, that did not work. Also loosened the AIO a bit as I've seen suggested, that didn't work. I am just hoping its not an issue with the CPU. Would rather it be the motherboard or the RAM.

Which slots work when you use only two modules? If it's only A1/2 or B1/2, you might need to pull the CPU and check the pins for damage.

On your motherboard the slot layout is [CPU Socket] |B1|B2|A1|A2|

 

[Zebidiah]

Which slots work when you use only two modules? If it's only A1/2 or B1/2, you might need to pull the CPU and check the pins for damage.

On your motherboard the slot layout is [CPU Socket] |B1|B2|A1|A2|

When booting with 2 sticks installed, every slot works fine with every pair combination of the RAM. I was able to successfully boot every time with no failures when testing that.

 

[Grobe]

You should test if the RAM sticks are in fact in good shape. The proper tool for that is Memtest, is a part of UBCD and also included as a boot option on most modern Linux distros (iso images) <list>.