Z77A-G43 - DRAM banks 1&2 acting up.

Question

Hey, guys. Thanks in advance for your time. I know it gets busy around here.
I am putting together a new system for the wife, and have an odd little issue. The DRAM banks 1 & 2 cause a pre-POST boot-loop when either are used. Banks 3&4 work perfectly. When a stick is in bank 1 or 2, the computer will power on, the fans spin, no video output, then it shuts itself down (regardless of what banks 3 & 4 hold). Repeats a few seconds later. All the usual trouble shooting has gone down. BIOS is all out-of-box default. All the components are brand new, but regardless were systematically replaced/removed one by one to narrow it down to these 2 ram banks. Needless to say, the RAM is fine - tested in two different computers. The memory banks are clean, new, with no visible dirt or damage. It's just odd.
Code: [Select]
1   2   3   4     <- Bank # ... X = used ... O = empty
X   X   X   X = FAIL
X   O   O   O = FAIL
O   X   O   O = FAIL
X   X   O   O = FAIL
O   O   X   X = OK
O   O   X   O = OK
O   O   O   X = OK
The RAM in use is Kingston HyperX DDR3 1600MHz PC3 12800 4 GB (4 identical sticks = 16gb total) (KHX1600C9D3K2/8GX ). With RAM in memory banks 3 & 4, BIOS tones it down to 1333 from 1600, but that's the least of my worries. BIOS shows the timing as 9/9/9/24 and the voltage around 1.45 (can't remember exactly) even when it's increased to 1.65 (as suggested by the sticky). I also tried going 1 stick at a time but it started acting up as soon as I put anything in bank 3 or 4. There's just a lot of BIOS options that I simply don't know what they do.
I realize you guys have seen a lot of issues and was curious if you wouldn't mind lending a hand? I know my way around a computer, but certainly don't have the specialty knowledge particular to these pieces of hardware that you guys do. Any help is very appreciated. Please let me know if there's any information I can provide. I am dumping anything I think could be remotely relevant in this message. I really hope it's not a faulty board. Between disassembly and shipping, that would be an awful hassle.
Here's what I'm working with:
MSI Z77A-G43 (BIOS v2.2B2)
Kingston HyperX DDR3 1600MHz PC3 12800 4 GB (4 identical sticks = 16gb total) (KHX1600C9D3K2/8GX )
Intel Core i5-2500 3.3ghz
Nvidia GeForce GTX 550 Ti 2gb
PSU: Cooler Master GX 750W (RS750-ACAAE3-US)
A-Data 120 GB SATAIII Sandforce SSD (AS510S3-120GM-C)
Western Digital Caviar Green 2 TB HD (WD20EARX)
Case: Cooler Master HAF 922 (RC-922M-KKN1-GP)
No OS has been installed. I didn't want to get too involved until I knew the hardware was staying put.
Thank you again for your time.

Answer 1

Quote from: Jack on 14-April-12, 13:42:19
I think the potential explanations for your problems are only a few.  We can, I think, exclude a memory compatibility problem, since the sticks work fine in other slots.
In my oppinion, what we are looking at is one of the following things:
1. A problem with the memory controller (which is inside the processor) = defective CPU
2. A pin-contact problem between the CPU's contact pads and the board's socket pins causing certain memory slots to be improperly connected to the CPU's memory interface
3. A short-circuit problem, blocking the functionality of the memory slots (test the board outside the case on a non-conducting surface)
4. Defective memory slots or a problem in the underlying circuits = defective board
At your suggestion, I have made a couple of attempts to reseat the CPU (regarding #2). I realize that was a long shot, and not surprised to see no difference. I just wish I had another LGA 1155 CPU to swap out and test #1. I'm going to continue to brainstorm this for a few days before putting in a RMA request.