[SOLVED] New RAM Not Detected

[TimothyK]

I have 2 8GB sticks and am installing 2 more 8GB sticks, they are exactly the same brand, model etc. I've put the new ram in DIMM slots 1 and 2 and it worked fine it seems DIMM slots 3 and 4 aren't detecting any RAM when I put the sticks in. As far as I can tell the system should support 32GB of RAM. Is there something I can change in BIOS? Is the motherboard faulty? What should I do?

Things I've tried:
-Verifying the new RAM sticks work.
-Testing old RAM in slots 3 and 4, both with and without RAM in slots 1 and 2 (not detected in slots 3 and 4)
-Testing a new RAM stick with an old RAM stick in slots 1 and 2 (worked fine).
-Loosening CPU cooler assembly


System Specs:
Alienware Aurora R4
CPU: Intel Core i7 4820K
Motherboard: Alienware A00, BIOS: A11 (Most recent I could find)
RAM: Kingston HyperX FURY 1866MHz DDR3, 2 x 8GB sticks
GPU: Nvidia GeForce GTX 1060 3GB

 

[PC Tailor]

I have 2 8GB sticks and am installing 2 more 8GB sticks, they are exactly the same brand, model etc.

RAM modules are only guaranteed in the form sold (from the same pack). So it's a 50/50 gamble whether a new set of modules will work with the old. This is because the manufacturing of the modules changes frequently, making them the same make/model/timings is irrelevant. That is just a way to try and minimise potential conflict, but not eliminate it.

Does the new RAM work by itself normally?
Have you confirmed whether it is the mix of RAM or if it is specific RAM slots that are the issue?
Have you tried JUST the old RAM in the last 2 slots?

If it appears to be just the last 2 slots not functioning, may be worth releasing some pressure from your CPU cooler, too much pressure on the CPU from the cooler can commonly cause RAM slot malfunctions.

 

[TimothyK]

I have tried the old RAM in the last 2 slots and it wasn't detected. I Will try loosening the CPU cooler. I'll post the results.

Edit: I tested one old stick with one new stick in slots 1 and 2 and they worked fine together.
I loosened the CPU cooler a bit then tested, and repeated until the CPU cooler was very loose. The RAM sticks in slots 3 and 4 were not detected at all.

 

[TimothyK]

The new RAM works both paired with an old stick and with 2 new sticks in slots 1 and 2.
It appears to be slots 3 and 4 that are the issue.
I've tried JUST the old RAM in slots 3 and 4, it wasn't detected.

I loosened the CPU cooler a bunch and tested the RAM in slots 3 and 4 multiple times with no success.

 

[PC Tailor]

How long have you had the motherboard?
So all RAM sticks work individually, but none work in the last 2 slots?
Presumably you are running each set of modules in the appropriate channels as per your MB manual?

 

[TimothyK]

How long have you had the motherboard?
So all RAM sticks work individually, but none work in the last 2 slots?
Presumably you are running each set of modules in the appropriate channels as per your MB manual?

I've had the Motherboard for around 5-8 years.
That is correct. Each RAM stick works individually and together in the first 2 slots but not in the last 2.
Appropriate channels? What does that mean? I followed the instructions in the manual. I don't remember it mentioning channels.

 

[PC Tailor]

I've had the Motherboard for around 5-8 years.
That is correct. Each RAM stick works individually and together in the first 2 slots but not in the last 2.
Appropriate channels? What does that mean? I followed the instructions in the manual. I don't remember it mentioning channels.

Your motherboard will run on dual channel architecture more than likely, basically 2 of your RAM slots run on one channel, and the other 2 slots run on another, effectively allowing you to double your bandwidth for RAM access.

If you installed the RAM as per your motherboard manual exactly, then it will typically tell you to install in certain slots (because of the channels).

Sooner sounds like it could be a motherboard fault then if quite simply the last 2 slots do not work regardless as to which RAM module is in them.

 

[TimothyK]

Your motherboard will run on dual channel architecture more than likely, basically 2 of your RAM slots run on one channel, and the other 2 slots run on another, effectively allowing you to double your bandwidth for RAM access.

If you installed the RAM as per your motherboard manual exactly, then it will typically tell you to install in certain slots (because of the channels).

Sooner sounds like it could be a motherboard fault then if quite simply the last 2 slots do not work regardless as to which RAM module is in them.

From what I understand slots 1 and 2 are channel 1 and slots 3 and 4 are channel 2. So it seems channel 2 is not detecting RAM.

 

[TimothyK]

Is there anything I can do? I'm not sure what to do next.

 

[PC Tailor]

Is there anything I can do? I'm not sure what to do next.

Replace the motherboard under warranty is the best option. If it's still under it. If not, replacing for new.
You've eliminated RAM from being the issue, you've identified it's the motherboard slots themselves.

Realistically the only points of fault at that point is CPU or Motherboard.
It may be worth reseating the CPU and in the meantime checking for any bent pins in the socket for example. But it's more likely the motherboard being as you've ran the PC for long enough.

 

[TimothyK]

Thanks for your help PC Tailor. I'll return the RAM. It's not worth replacing the motherboard (They are too expensive).