F3-10666CL8D-4GBHK and Asus M4A78T-E doesn't post

[Shepherd]

Here's my system..
CPU: PhenomII X4 945
MB: Asus M4A78T-E
4x F3-10666CL8D-4GBHK

My problem is the system will only post with one stick in the B1 memory slot. While that one stick is in, it'll pass memtest86+. Memtest reports the timing correctly, but doesn't show it as ddr3-1333, shows something like ddr400. I'll test two sticks individually, they'll pass. But once I put them in together, the system won't post, no beeps, just the fans running. Asus support site leads me to believe the memory has failed. This happens with all 4 sticks.

I've configured the bios according to the few forum posts that have the same combo MB and memory as me, and tried a few others too. But always with the same result. Initially, the system started with random bsod and the occasional freeze (once memtest froze while testing all 4 sticks at once). Over the past week it began not posting. Does it sound like the memory is bad? Or does anyone have any suggestions for me to try?

Thanks

[GSKILL TECH]

You have 4 sticks, each stick should POST in slot A1. Let ASUS know that you have 4 modules, the memory is not defective, and you need a new motherboard.

Thank you
GSKILL TECH

[Shepherd]

Are we sure it's the motherboard? Because today the problem behaved differently. All 4 sticks worked in any slot and memtest actually was reporting the proper sticks most of the time. I decided to leave two sticks in A1 & B1 and run memtest overnight. In the morning memtest was frozen on pass 6 with a screen full of errors. The problem is so intermitent it's driving me crazy. I guess next thing I'll do is test each stick individually for an extended time. Other than that, is there anything else I could be doing to figure this out?

[GSKILL TECH]

If you'd like, send them in to us for new replacements. Request to have them tested, and we will make sure you receive 4 working modules that sync together.

Thank you
GSKILL TECH

[Shepherd]

Thanks for the offer. I have an inquiry in at Asus to see what they say. I'm kinda leaning towards the motherboard now because the system appears stable with one module in slots B1 or B2, but won't post without any beeps if a module is in slots A1 or A2.

One question though, is it normal for memtest to report a single module as DDR400 200Mhz with 8-8-8-21 timings, but report 2 sticks at 1333MHz, same timing? I have the bios set as 1333MHz with 8-8-8-21 timings. I'm just wondering if that's why system appears stable with one module, because the memory is running much slower?

[GSKILL TECH]

No, I don't see why it would go to DDR3-400 at all. If the memory is actually defective, it will error at DDR3-400 too. If it is not enough voltage at full spec, or bad settings, then yes going down in frequency can stabilize since the motherboard can automatically support lower frequencies.

Thank you
GSKILL TECH