ASUS M4A78 PLUS does not work with F2-6400CL5D-8GBPQ

[RobScott]

Model of the motherboard: ASUS M4A78 PLUS
Model of the memory: F2-6400CL5D-8GBPQ
Model of the CPU: AMD Phenom II X4

Problem:
PC does not power up at all -- no POST, no beep code.
If I remove the RAM, I get a "memory error" beep code.
If I replace the RAM with a 2GB stick from another PC, everything boots fine.

I suspected that the first batch of RAM was bad, so I returned it; the replacement does exactly the same thing.

The QVL (Qualified Vendor List) in the motherboard manual lists the following G.SKILL memory:
2GB - F26400CL5D-4GBPQ
2GB - F26400CL4D-4GBPK
4GB - F26400CL5Q-16GNQ

Perhaps unwisely, I assumed that the 8GB product was the equivalent of two 4GB of the "approved" memory sticks. Was I incorrect, and this memory is incompatible with the motherboard?

Thanks for your help.
Rob

[Tradesman]

Have you tried with a single stick? Do you have the latest BIOS? What CPU are you running, there are a number of Phenom II X4's?

Your mobo is rated for up to 16GB so the sticks should work, may be a problem of not enough voltage to the RAM or the MC, could also be the BIOS isn't reading them right, could be a few things.

I'd try a single stick and see what happens, if it will boot take a look at your BIOS settings, and then try the second stick again.....if still not working if you can get it to boot w/ one stick, pls post your BIOS settings

[RobScott]

Thanks for your response!

Have you tried with a single stick?

Yes, I have tried it with a single stick without success.

Do you have the latest BIOS?

Yep.

What CPU are you running, there are a number of Phenom II X4's?

The CPU is the Phenom II X4 945 -- sorry about that, I meant to include it in my OP.

Your mobo is rated for up to 16GB so the sticks should work, may be a problem of not enough voltage to the RAM or the MC, could also be the BIOS isn't reading them right, could be a few things.

Since I am able to boot it with a stick stolen from my son's PC, I will try to tweak and BIOS settings.

Thanks again,
Rob

[GSKILL TECH]

What slots do you have them installed in? They must be in different channels as the CPU can not operate them in the same channel.

Thank you
GSKILL SUPPORT

[RobScott]

What slots do you have them installed in?

When I was using both sticks, they were in A1 and B1. With a single stick, it was in A1. As I mentioned earlier, with a "stolen" stick from another PC, the system boots fine.

I tried a number of BIOS memory settings to no avail. The most extreme settings I tried are as follows:

Memclock Value 200MHz
CL 6
tRCD 6
tRP 6
tRAS 18
tWR 6
tRRD 5
tWTR 3

It still will not boot with the G.SKILL RAM, but boots fine with the other RAM.

Any other BIOS settings I should try?

Thanks,
Rob

[Tradesman]

Might try command rate/command timing at 2N, many AMD mobos default to 1N

[GSKILL TECH]

Seems like there is some sort of incompatibility with the BIOS. Contact ASUS and they should be able to get this resolved.

Thank you
GSKILL SUPPORT