F3-12800CL8D-8GBXM + Asus P8Z68-V LE = no POST

[jeffk]

Built new system with Asus P8Z68-V LE SandyBridge motherboard, Core i5-2500, and F3-12800CL8D-8GBXM memory. Machine won't POST with both DIMMs installed, but will boot up with only one installed. I've updated to latest BIOS, and tried default and XMP settings in the BIOS. It will work with either DIMM installed singly, and I tried different slots so it doesn't seem to be a bad DIMM slot. Suggestions?

[Tradesman]

Are the sticks in slot 2 and 4 (counting from CPU)....try with one stick, set BIOS to defaults, then install sticks in 2 & 4, if goes to BIOS, enable XMP, and select 1600 profile

[jeffk]

Yes, I'm using slots 2 & 4 since slot 1 is blocked. A single DIMM in slot 2 works fine (either DIMM). But adding the second DIMM is slot 4 doesn't work.

[Tradesman]

If both work in 2, might be the mobo or the CPU's MC (Memory Controller)...any chance of having or borrowing another set of sticks to try?

[eNeutral]

If some of your DIMM slots don't seem to work, your heatsink backplate might be touching the back of the motherboard causing a short. I have a P8Z68-V LE and I had a similar problem. The solution was to use the heatsink's included electrically-neutral plastic spacers between the motherboard and the backplate. That solved it for me.

[Tradesman]

eNeutral,

nice call, also can happen from a loose screw in the mobo attaching to the standoffs

[jeffk]

I'll check that possibility. I actually got an RMA replacement for the motherboard, but haven't had a chance to do the swap yet. If I'm lucky and it's a short I won't have to.

[Tradesman]

Let us know

[jeffk]

Replacement motherboard fixed the problem. I really don't see how it could have been heatsink plate causing short, because the contact points are coated specifically to prevent that.

[Tradesman]

Glad to hear all is well, Enjoy!