Strange K9N2 SLi Platinum issue getting progressively worse

Question

Quickspec:
AMD Athlon64 X2 6000+ ADV60000DOBOX
K9N2 SLI Platinum
G.SKILL 8GB (4 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500)
2x BFG Tech GeForce 8600 GT OC2 w/SLI bridge installed
Western Digital Caviar Black SATA 1TB
No additional cards
Microsoft Windows 7 x64
PC Power & Cooling Silencer 750 -- 750W Continuous @ 40C (825W Peak)  +12VDC @ 60A (Single Rail)
I put together my system (http://valid.canardpc.com/show_oc.php?id=628222) in April of '09 and everything has been rock solid.  About 3 weeks ago, I started seeing strange graphical glitches, which can only be remedied by a system reboot. See below:
Initially, I thought that the issue may have been software related, as I could screenshot the problem, and noticed that the problem would occur only after waking from sleep mode, and only while playing fullscreen games.  Before assuming anything, I ran diagnostics and checked my temps, all of which were in spec, so I decided, maybe I had lost my primary video card. I tried each of my SLi cards independently with the same result. I've also tried using each PCI-E slot with similar results.
I moved on to test memory with Memtest86, which would lockup @ 5% through its first test. So I started sequentially removing RAM sticks until it ran.  After pulling out two sticks of ram, I thought I had nailed down the issue, things were stable again, but the system would periodically not POST, no VGA, nothing. Diagnostic LEDs would be RED|GREEN|GREEN|GREEN but would boot normally after a power cycle.
After a couple days of stability, the video glitches came back.  At this point, I'm thinking it could be the Mobo itself. Upon boot my LED Diags go RED|GREEN|RED|GREEN and don't change.  The system is failing to POST most of the time, and when it does boot, just completely dies under any stress whatsoever.
Obviously, I would imagine, it could be a power issue, but I have a solid PCP&C Silencer 750 which I would find hard to believe is causing the issue. I could test voltages, but I'm doubtful this is the issue.
Any thoughts on what I might try next?

Answer 1

Quote from: Stu on 04-February-10, 03:18:53
The graphics corruption your screnshot shows would seem to be symptomatic of a failing VGA card.
Yes, but not only. I doubt that's VGA failure for this case.[He got 2 VGA's, tested each one alone with no change, Both VGA to be failing sound not much realistic]
Unstable system memory can cause the same artifacting/visual corruption
Quote
I moved on to test memory with Memtest86, which would lockup @ 5% through its first test. So I started sequentially removing RAM sticks until it ran.  After pulling out two sticks of ram, I thought I had nailed down the issue, things were stable again, but the system would periodically not POST, no VGA, nothing. Diagnostic LEDs would be RED|GREEN|GREEN|GREEN but would boot normally after a power cycle.
One more pointer to exclude the VGA{s}
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#  G.SKILL 8GB (4 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500)
Can you provide exact models? or link to manufacturer?
Quote
#  G.SKILL 8GB (4 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500)
Quote
#  AMD Athlon64 X2 6000+ ADV60000DOBOX
Quote
which I linked in my OP http://valid.canardpc.com/show_oc.php?id=628222,
RAM : 8192 MB DDR2 Dual Channel
RAM Speed : 387.6 MHz (Unknown) @ 5-5-5-15
Slot 1 : 2048MB (6400)
Slot 1 Manufacturer : G.Skill
Slot 2 : 2048MB (6400)
Slot 2 Manufacturer : G.Skill
Slot 3 : 2048MB (6400)
Slot 3 Manufacturer : G.Skill
Slot 4 : 2048MB (6400)
Slot 4 Manufacturer : G.Skill
With all four memory sticks installed drop memory divider to 667.
[current in use is default 800, you can do that from BIOS Setup,
Cell Menu adjust option named "FSB/DRAM Ratio", apply to either "333", "667", "1:1.67", "5/3" {all mean the same}]
The CPU's [AMD Athlon64 X2 6000+ ADV60000DOBOX] memory controller, can't handle them at full speed.
[For more details refer to this topics:
==> https://forum-en.msi.com/index.php?topic=130043.0
==> https://forum-en.msi.com/index.php?topic=120827.0
Other tips:
* Test each one memory stick alone with >>Memtest86<<,
use the 1st DIMM close to CPU socket to isolate if you have an defective stick.
* You can apply memory voltage in BIOS Setup recommended by memory vendor if need[2.0 - 2.1V, check specifications at memory vendor for your sticks]