ASUS M3N78-AM Memory Problem

Bit Baby

ASUS M3N78-AM Memory Problem

I had 2 x 1GB memory modules which have worked well for about 6 years. After updating to Windows 10, I decided to upgrade to 2 x 2GB so used the Crucial memory scanner which identified compatible memory. It came today but after fitting, failed to boot up except in Safe Mode or with only one memory module fitted. I have updated the BIOS to the latest on the ASUS website with no improvement.

 

I ran CPU-Z and found that instead of the memory running at 400MHz, it was only running at 371MHz so set it manually to 333MHz but this made no difference, giving a reading of 325MHz in CPU-Z.

 

Can anyone help in getting the memory working before I return it?

3 Replies
JEDEC Jedi

Re: ASUS M3N78-AM Memory Problem

Did you try each module by itself to make sure each one works by itself?

 

Double check each module to make sure they are identical.   I'm assuming they are 800MHz or PC2-6400 rated by your posting.

 

With default CPU, memory and power settings, does the BIOS see the new memory correctly?

 

You can also try running Memtest86+.

Bit Baby

Re: ASUS M3N78-AM Memory Problem

Yes, both modules work on their own and with one of my old 1GB modules.

 

Yes, both are identical.

 

The BIOS does see all the memory and go into Dual Channel mode.

 

I'd have to run Memtest86+ on a bootable CD as Windows 10 will not boot unless in Safe Mode?

JEDEC Jedi

Re: ASUS M3N78-AM Memory Problem

Since Crucial sells 667MHz memory for this motherboard, it is possible your motherboard & CPU combination is only able to run at 742MHz (2x371MHz for DDR2).   It seems the Asus & Crucial information show the ability to use memory up to 1066MHz, however, this is likely dependent on the CPU you have installed as the Asus documentation shows a limitation with 1066MHz memory.

 

I haven't used CPU-Z in a long while so I'm not sure how accurate it is at determining memory speed or whether some other software could be interfering with the results.  I believe you have to double the results for DDR2 memory.

 

Does your BIOS/UEFI settings show the proper speeds?

 

Memtest86+  needs to be burned to a CD or USB drive and the system booted from it.   I believe it may show the memory speed, but I'm not sure if it is just reading it from the SPD information or not.

 

Your memory will only run as fast as the CPU & motherboard can handle.  Verify what memory speed your CPU is designed to operate.   While this motherboard series may be capable of faster speeds, it is possible you have an early version of the motherboard where faster speeds are not well supported or perhaps some supporting electronics or even the power supply are failing and can no longer support the faster memory speeds.