New AMD system - defect?

[Guest]

Hi

5 days ago I bought new system hardware. An Athlon II x4 640 boxed, Asus M4A 785TD-V EVO motherboard, 2x2GB Corsair DDR3 RAM, a 430W be quiet ps, and a 500GB WD hard disk. I put it into my old ATX case, using the old IDE DVD drive and a 54mbit wireless PCI card.
I installed Windows 7 without problems, but soon after had random blue-screens (basically everytime different message) ranging from driver problems with some ati*.sys to rtl8185.sys to usbfilter.sys. at first i suspected some driver problem so i installed latest driver for video, motherboard, sound, and network. i also ran a memtest that didnt give any errors. i also ran prime95 which very quickly resulted in fatal errors "Rounding was 0.5, expected less than 0.4". next i suspected the WLAN card since it's along with the DVD drive the only component i kept from the old system. i removed it but still the same. prime95 detects errors and soon after the system crashes.
i tried booting into ubuntu from the install CD, but it doesnt even boot, so i'm very concerned. the system is new, so a hardware defect is so unlikely and yet i'm quite sure there is no software problem.
i did no overclocking (barely touched the BIOS). the temperatures seem to be ok (CPU under load at 50 and sys at 40).

Is there anything I forgot about? Any help appreciated. Should I return the CPU, or is it the mainboard? What's wrong

 

[iam2thecrowe]

reset BIOS to defaults, update BIOS, check RAM with memtest86+, check PSU voltages with hwmonitor (could be a power supply problem) what brand is the PSU? What video card are you running? Try each stick of memory on its own.

 

[Guest]

BIOS reset done
linux crash during boot
memtest was fine as i wrote

PS brand is be quiet!
VCORE voltage between 1.376 and 1.392
3.3 V is 3.376 to 3.392
5V is 4.915
12V is 12.049

it's no extra video card. just the onboard ATI HD 4200

using each RAM alone, prime95 seems to run without errors, no matter which one i use. strange...

 

[popatim]

which specific ram did you get?

 

[Dekasav]

Bump the voltage on the RAM a step.

 

[Herr_Koos]

Sounds like RAM trouble to me. You didn't enable some sort of auto-overclock setting in BIOS that may be pushing the RAM voltage up?

 

[iam2thecrowe]

sometimes dual channel ram setting can cause problems if you have a fault with the motherboard. disable dual channel, if you can, to test this. Also try different ram slots.

 

[Guest]

RAM is 2 times Corsair CMV4GX3M2A1333C9 it has 2GB each.

BIOS settings were restored to original. it does have some overclock stuff but i didn't touch any of them.
i don't see where i can disable dual channel in BIOS but i'll try different RAM slots now...

 

[Guest]

OK here is what i've got so far:
Single RAM seems stable
Both RAMs in same channel (one blue, one black) gives single channel and seems stable
both RAM sticks in different channels (either both blue or both black) are unstable.

so it seems to be Dual Channel causing this. i'll try updating BIOS from 2103 to 2105.

 

[Guest]

OK, BIOS is updated.

Still, using same coloured RAM slots (dual channel) keeps crashing.
well now at least i know its neither CPU nor RAM... but mainboard.

any ideas what to do?

 

[mosox]

Dual channel is blue and black on that mobo, if the manual says different, it's a mistake. Also lower the CPU voltage to 1.25-1.3.

 

[Guest]

are you sure? CPU-Z says single channel with blue and black and dual channel when both colours are the same and that agrees with the manual. both wrong?

 

[mosox]

Which slots are A1 and A2, also B1 and B2?

 

[Guest]

the order is blue blue black black and B1 A1 B2 A2

 

[mosox]

OK, I think the manual screwed up I've seen a lot of this. Try the black slots, A2 and B2.