ASUS Z97A, only 3 out of 4 RAM slots work

Peter_DE

Commendable
Sep 23, 2016
4
0
1,510
Hey guys,

first things first: Sorry in advance for any english mistakes, I'm from germany, I'll do my best :)

I am maximum confused right now. I bought the parts of my gaming pc about two years ago. Everything worked quite fine till now - well, the SATA controller on my motherboard was and is broken, but I got a PCI-E SATA-Controller as a workaround, which does it's job.

So, today after work I started my pc (as always) and got the first bluescreen since ten years or so. SYSTEM_THREAD_EXCEPTION_NOT_HANDLED or something. The PC shut itself down, tried to restart itself a few times. The first three times it got into the boot screen of windows, then only to the ASUS logo, then it restarted itself every 2-3 seconds and the screen was black. Sometimes the DRAM led was shining, sometimes the VGA led.

I tried three hours to fix this error, reconnected all PSU cables, removed the RAMs, removed the graphics card. changed the CMOS battery, put everything but the RAMs back in and after a while - I finally got into the boot screen.

So: I inserted one RAM after another and restarted the computer every time. It worked fine, till I inserted the 4th RAM. Then I got the same issues as mentioned above. Screen black, VGA/DRAM leds shining. I checked this quite a few times and got to this conclusion: It does not matter which RAM I insert - it does not metter in which slot - it just has to be the 4th RAM. Slot 1-3 work, as long as no RAM is inserted in the 4th slot. Slot 2-4 work, as long as no RAM is in the 1st slot, and so on.

Does anyone have an idea? I googled for hours and found nothing. I have a bad feeling, that the motherboard may be finally broken.

My system:
ASUS Z97-A, newest BIOS
Intel i7-4790k
4x 8GB Corsair Vengeance DDR3, 1600Mhz, CL9, 1.5V
EVGA GTX 980 SC
Windows 10 Professional x64

Best regards from Germany
Peter
 

Peter_DE

Commendable
Sep 23, 2016
4
0
1,510
No, they came in two packages (each 2x8GB). I tried what you suggested, unfortunately it didn't solve my problem. Then I tried activating the XMP profile, still nothing. Sometimes it even boots a little bit with 4 inserted, but then I get strange errors like "no keyboard found" or "IRQL_NOT_LESS_OR_EQUAL"... But most times the screen just stays black and the VGA_LED or the DRAM_LED is red.

One RAM removed -> BIOS and Windows 10 work perfectly. :(