DDR3_B2 slot causes Single Channel works only

[GrzegorzG_]

I have 4 memory sticks DDR3. When i put all of them then they work donly on Single Channel. Also - when i put two of them to slots 1+2, 2+3, 1+3 then they work on Dual Channel. But when i put memory stick to slot 4 then it works on Single Channel.
What could be the reason and what other info is needed to help with the issue?

regards.

 

[COLGeek]

Are all of the modules (memory sticks) the same make/model?

 

[GrzegorzG_]

I will explain all situation in details:

MY HARDWARE:
Motherboard: ASRock 970 Extreme3
CPU: AMD FX-8320
RAM: TRANSCEND 2GB 2400MHZ DDR3 - 4 sticks

SITUATION:
1. I used this set for a few months - all worked fine. RAM was working on dual channel w/o any problem.
2. A few days ago I removed my CPU fan to clean it as CPU started to heat (60+ 'C on cores). I wanted to OC it a bit. During OC on CPU I found that my RAM is on auto settings but its frequency is 800MHz (strange as default should be 1333MHz). At that stage I didn't change RAM settings.
3. I put the heat paste on CPU, mounted fan and turned on the PC
4. Since then PC started to be unstable - i.e. hangs a lot, even in BIOS on default settings (i removed BIOS battery even). On launch motherboard beeped 3 times that means some RAM problems.
5. I checked all sticks one by one, and the result is that all sticks are fine - when I put them in pairs to slots DDR3_A1, A2, B1 - they all work on dual channels, but if any is put to slot DDR3_B2 then it starts to work on single channel.
6. Now all seems to be stable – I use 4 sticks – they work on 1333MHz default frequency, BUT ONLY SINGLE CHANNEL 🙁. It means 8GB of RAM but only 4 are available.

If any additional info is needed then I will provide it.

Thanks a lot for any help!

 

[GrzegorzG_]

Additional question - how to remove this "frame" (i don't know the correct name of that thing) to get to the socket pins?

I checked all pins on CPU but have to be 100% sure that all pins on socket are fine.

 

[COLGeek]

Are you still running the OCed CPU settings, or are you at stock speeds?

 

[GrzegorzG_]

Stock - all is set as default.

 

[COLGeek]

Make sure nothing is inside the memory slots (dust, old thermal compound).

 

[GrzegorzG_]

Slot is 100% clear.

 

[COLGeek]

You can try bumping up your voltage in the BIOS for your memory. Use the smallest increment you can to see if it makes a difference.

 

[GrzegorzG_]

I tried from 1.50V to 1.60V - unfortunately without any success 🙁

 

[COLGeek]

Try one more to 1.7