[Problem description] If you use AT power cable to do AT power boot will become boot fail always after clear cmos. PS. ATX power cable using without such problem. [Root cause] This problem is the limitation of VIA chipset. When it power on by AT mode, clear COMS will make chipset go to an unknown situation. it only happend with few boards. [Suggest recovery method] When you met such AT boot fail after clear CMOS, pls do below action to let SB retrutn to normal state. 1.AT Power on (fail happend) 2.Press Power button CN20 3.Press Reset butoon CN19 4.You will see the board boot again normally. thx ACL_AE