No dual channel / Bad RAM Slots in Z75 Pro3?

[NerevarineX]

Hello everyone, I just got a motherboard(Z75 Pro3) that has a peculiar problem for my i7-3770 after my previous one died under mysterious circumstances (H67DE3), anyway there is this problem with RAMs.
There are 4 slots, A1, A2 and B1,B2 respectively. I will try explaining it in cases, as that would make more sense.
Case 1 and 2: Use 1x4GB in A1(Case 1) or A2(Case 2), working okay. single channel.
Case 3: Use 2x4GB RAMs in A1 + A2, but only one of them is detected in single channel(4GB at A2 precisely).
Case 4, 5, 6: Using 1x4GB in B1(Case 4) or B2(Case 5) or 2x4GB in Both(Case 6) causes the system to malfunction, as when i press the power switch, it turns on, waits for 5 secs and then turns off, turns on again, turns off, in a loop, no display.
Case 7, 8, 9, 10: Using A1, A2 and B1(Case 7) OR using A1, A2 and B2(Case 8) OR using A2, B1 and B2(Case 9) OR using all slots(Case 10) causes the same reaction as i get in Cases 4,5,6.


What is causing this? faulty DIMM slots? My processor? my previous motherboard didn't have this problem, and because the guy I got this motherboard from swore that he used dual channel on it and hasn't experienced this problem before, I could give it back and let him test it or get another motherboard but that would take days and i don't want to waste time. Thanks for your attention, sorry if i made it a bit more complicated with the cases situation, but I hope you guys have seen this kind of problem before and point out the culprit.

 

[Darkbreeze]

Slots A2 and B2 are the slots designated for two module dual channel operation. I do not see any scenario above where you tried this configuration AND THEN WAITED FOR IT to train the memory.

Install your modules in slots A2 and B2, then with the power off unplug the power supply from the wall. Next, remove the CMOS battery and leave it out for five minutes. During that time, press the power button and hold it down for 30 seconds. Reinstall the CMOS battery, plug the power back in, power on the unit and then allow it to train the memory. It should not take more than five attempts at training the memory to succeed. Allow the system at least five attempts to complete the memory training before abandoning the attempt.

If it does, then it is likely you have two modules that are not compatible with each other, or one of the modules is faulty or the motherboard is faulty. It's also possible, if the CPU has been out of the socket or you have recently built this system (even though it's a pretty old platform I realize that some folks find these old parts and do what they gotta do) that this is a problem due to bent motherboard pins in the CPU socket. Bent pins can have a direct effect on the memory controller and a single bent pin could affect only a specific memory slot, or two slots, or all slots, or none, and affect something entirely different.

Were these memory modules purchased together, in a matched set, or are they distinctly different model numbers or even same model numbers that did not come together in a kit?

Could definitely be a bad motherboard, but elimination of all other possibilities is the only way to really determine that.

 

[Calvin7]

It could be your choice of memory. Try listing part number(s) or link to it.