GA-78LMT-S2P - 2nd RAM Slot Won't Work?

[pathos]

My motherboard absolutely will not go into post if the DIMM slot furthest from the motherboard has anything in it.

I've tried both a 2GB stick and a 4GB stick in the closest DIMM slot and the computer boots perfectly. But if the stick is in the furthest slot OR if both slots are filled, I just get a black screen; no post, no nothing.

I thought it was a defective DIMM slot, so I exchanged the motherboard for the same model and am getting the same issue.

Not sure what else to try.

[absic]

Hi there,

sadly you don't tell us some very important information so it is a little hard to say exactly why the slot doesn't seem to work.

If you could post back with some more information about your system hardware it would really help.
What CPU, RAM and other hardware are you using? Also which revision is your motherboard and what BIOS version are you running?

[Dark Mantis]

As absic says there is rather a lack of information to go on but my guess (at this point that is all it can be) is that the CPU with the memory controller on it is faulty.

[pathos]

The CPU is a Phenom II X4 840.  I've tried both the RAM that came in my ASUS desktop and the store-brand RAM I got from Micro Center.  I THINK the motherboard is Revision 3.1.  And the POST screen says that the BIOS is Version 6.00PC.

[absic]

Hi again,
if you go into BIOS and press the "F9" key when you are at the BIOS homescreen another window opens and shows you some more detailed information.

If you do this you will be able to find which BIOS version you are running. It will be either F1, F2, F3, F4 or FA or FB. depending on the revision of the motherboard.

If you are running the rev 3.1 version of the motherboard and the BIOS is not F4 then I would recommend updating to this version. If the current BIOS is F1 or F2 then you will need to use the @BIOS utility to update the BIOS. If it is F3 then I would recommend using the QFlash utility.
If you are running the rev 4.0 motherboard and the BIOS is FA then update that to FB using the QFlash Utility.

[pathos]

Ok, it says BIOS Version F4 / Backup F4.

[absic]

Have you made any changes to the settings in BIOS in your efforts to solve this problem?

Before trying to move forward it would probably be best if you go into BIOS again and load "Optimised Defaults" to restore BIOS to it's basic position so that we are working from a known baseline position.

It would also help if you could let us in on the secret of which RAM make and models you are using, thanks. 

[pathos]

I went in and hit "Optimized Defaults" and my computer stopped booting.  Oops.  I had to go back in and reset the hard drive boot order, but now nothing's changed except that.

As for the type of RAM I'm using, really I have no idea.  It's store-brand DDR3-1333 RAM that I got from Micro Center; there's no other identification on the chips.  The other chips I've tried are whatever comes stock on an ASUS desktop.  All that are on these are a sticker that says "NANYA"

[absic]

Your real problem here can be a couple of things.

As Dark Mantis mentioned earlier, the Memory Controller is actually part of the CPU and if you have a problem such as your system is showing it could be due to a faulty processor.

There is the possibility of a faulty DDR3 slot on the motherboard but that would be unlikely especially as this is your second motherboard showing the same symptoms.

The third thing that could be wrong is your RAM. Without being able to say which brand you are using this is going to be the most likely suspect. You really need to buy a matched kit by a reputable manufacturer to have any chance of moving forward and it would be even better if the RAM you obtain is on the Qualified Vendors List for your motherboard or if the manufacturer's website state that it will work.