udating BIOS, clrearing CMOS, trying different RAM combos.... nothing worked...
Tomorrow I call ASUS support, I will let you know

Hello! Yesterday I bought ASUS's AT3N7A-1 , an Atom330 + ION GPU mITX mobo. It has 2 DDR2 ram slots and supports up to 4GB of RAM... BUT it cannot actually use them!!!! The BIOS says: 4096MB Installed, 768MB usable .... booting windows only gives 768MB of RAM! Further more using only 1x2GB stick sti...

thanks ilovejedd, I will try for now the 40x40x10mm fan... the one that came with the heatsink has a 40x40x20mm one btw... I wonder if I see a temperature increase... So the 945GC is indeed a HOT chip... damn intel on their previous model with the 1.2Ghz celeron cpu used a SIS chipset... and no fans...

hiya!!! I too have this awesome little mobo and plagued with it lame northbridge cooling solution... I removed the stock hs/fan and put this 159gr copper one : http://l.mydashop.info/da_shop/23-023.jpg http://l.mydashop.info/da_shop/23-023-1A.jpg http://l.mydashop.info/da_shop/23-023-2.jpg eBay link...

check the cables and try to reset the BIOS settings, but I doubt this will fix the problem, to me it sounds like a typicall half-dead motherboard... you could try a PCI SATA controller and work with this... cheaper than getting a replacement mobo but if your current one is indeed half-dead you shoul...