Yep, if your known good RAM doesn't work in either of the A slots then sounds like entire channel is fried. Make sure there isn't a setting in your BIOS to utilize both channels of RAM. If it is truly fried then your only option is to either buy bigger RAM sticks (expensive) or just buy a new mobo for $80. But yeah, that sucks sorry.
"Advice provided by Jade at www.customconnected.com "
They have one open box at $123 at Microcenter.
I can buy that one and then RMA my current motherboard