How can I get my A97-AR mb to recognize DIMM in the A1 and A2 slots?

[Hurm]

I have been using Ballsitix 2x4GB 1600mhz, and they are configured in slots B1 and B2 and work perfectly. I recently purchased Corsair Vengeance 2x4GB 1600mhz, and just like when I first attempted installing my Ballistix DIMM, I could not POST with sticks in A1 and A2.

I did check the User Guide that came with the mobo and it is not listed and I have upgraded the BIOS to 2501 (which I believe to be the most recent). To rule out incompatibility, I put one of the sticks of the Corsair in B1 and a stick of Ballistix in B2 and it POST and booted.

So the problem I am seeing is the A1 and A2 memory slots are not cooperating. Hoping I could find an answer here, as I often do!

 

[Hurm]

Found a couple possible solutions after searching more thoroughly, going to test them out.

 

[Dark Lord of Tech]

There is no guarantee , certain sets will be compatible.

Identical modules purchased in pairs at the same time is your best bet.

 

[Tradesman1]

What CPU cooler, if third party and too tight in a corner or side it can throw the CPU out of level (not getting full pin contact) and in affect losing a channel of your DRAM (the A channel here), try loosening the the cooler then snug it down screw tight

 

[Hurm]

There is no guarantee , certain sets will be compatible.

Identical modules purchased in pairs at the same time is your best bet.

You are most likely correct, but I had success booting with one stick of each brand.

 

[Hurm]

What CPU cooler, if third party and too tight in a corner or side it can throw the CPU out of level (not getting full pin contact) and in affect losing a channel of your DRAM (the A channel here), try loosening the the cooler then snug it down screw tight

I am using the stock cooler that came with my i5 chip. I did as you said and it seems evenly snug on there now with no changes.

I accidentally marked this as a solution, though I have yet to find one. I am slowly gravitating towards the fact that ASUS boards are not as good as I previously thought.