Problems displaying the amount of RAM?

Question

Iron

Hello!
What we have:
Mother Asus Sabertooth P67 rev1 (bios version 3602)
Processor Core i2500
DIMM: 4x2GB Kingston
Video: Asus GTX 970
The essence of the problem: After the next cleaning of the computer (every two months) after launch, I found that the system sees only 4GB out of 8GB. I went into the bios, he also sees only 4GB.
What have you been doing:

• 1. I checked in msconfig, the memory limit is not worth it
  

img

2. I checked the display of the bars - everything is fine

img

3. I changed the strips in places - to no avail. Only eat

nuance

I have slots A1, A2, B1 and B2 on my mother. I put two bars in A1 + B1 and A2 + B2 - everything works. But if you add a bar to any of these options in any of the free slots, it still shows 4GB and not 6GB.

4. Wiped the belly. The contact pad is normal, except for two bent legs, but they have been bent for 2 years already.
5. I changed the voltage on the DIMM, to no avail.
6. Changed the frequency from 800 to 1333 - to no avail.
7. Yuzal MemOK. To no avail
8. Changed the value of Memory remap (On and off)

img

9. Lowered the bios version and raised it (via EZ flash)

img

Help people. Otherwise, somehow buying two 4GB sticks is not ice, otherwise it will not help.

Answer 1

Memory slots can only work in pairs.
As for cleaning, it is still highly desirable to wipe the contacts in the DIMM connectors.
Well, there is another option - one of the dims just covered himself. If the system starts on one dime, then you can check by running it one by one on each.

Answer 2

Checked each DIMM separately and on each slot. Everything is working.

You can also try a complete enumeration of combinations (4! = 24), perhaps somewhere there is an individual incompatibility. Those. score all 4 slots, but in different combinations (only number the dice): 1-2-3-4, 1-2-4-3, 1-3-2-4, 1-3-4-2, etc. d. If you check the volume only in the BIOS, then it will not work out so long.