Thanks, both, for the help.
I've got 64 GB GSkill Ripjaw 1333 1.5v (9-9-9-24). All matched memory with sequential serial numbers.
I did more experiments last night, putting RAM in one module at a time into different slots; I got post and to bios. Yeah!
Now here's the problem: I can populate Channels B, C, and D and have 48 GB running and post and get into bios. But when I populate RAM into Channel A (either slot), I get the beeping again and the motherboard won't post. This happens whether there is only one module in Channel A with nothing populating the rest of the board, or when the other channels are full or partially full.
In short, if any module goes into Channel A, the beeping occurs and no post. I've switch the RAM around and tried different modules in A, but always the same thing.
So, could this mean that I've got a bad Channel on the motherboard? Channel A is the two memory slots just to the right of the processor, above the southbridge.
Or could there be some timing adjustments I need to make in bios to get all Channels working? Memory is running at stock 1333 according to Bios. I haven't changed anything.
I'm about to MemTest all the memory in the Channels that do work to try and eliminate that at least.
Thanks again for teh help., and anytoher ideas.
Mahlon