マザボ起動診断LED。Q-LED(ASUS 4-LED: CPU/DRAM/VGA/BOOT・順次点灯でBoot進行)・EZ Debug LED(MSI)・Q-Flash Debug(GIGABYTE)・POST Code LED(2-digit 16進・Hex code dictionary参照・AMI BIOS: 62=Chipset init, A0/Ax=IDE/boot・Intel spec 4 beep等)・Dr. Debug(ASRock)・High-end(Maximus Hero等)LED + Speaker + Reset・Boot fail Repeat Ctrl+F10でCMOS reset boot・2026年 DDR5 training fail対処BOOT LED orange長点滅重要。