it's generally quite difficult to run 3 different sticks of ram in this board ... different meaning different manufacturers and/or different timings.
preferred memory configs are: 1x512 in slot 1 (closest to processor), 2x512 slot 1,3, 3x512. Memory slot 2 is considered the "weakest", so avoid 1,2 and 2,3 or 1x512@2 configurations.
suggest you try each stick at stock speed in each memory slot. each should boot and run stock. Then leave one stick in slot 1 and try each of the remaining sticks in 3.
If I recall correctly from another thread, you may have burned up one of the sticks ... obviously you'll want to be wary of that stick.
my suspicion is that you'll only succeed at 1x512 in slot 1. Fix, of course, is to buy addtional memory to match one of the sticks ... or all new memory.
