Intel Desktop Board 21 B6 E1 E2 Manual Upd

The codes are typically listed in Appendix A: POST Code LEDs of the Technical Product Specification, not the quick-start guide.

If your board has a 2-character 7-segment display, it shows codes directly. intel desktop board 21 b6 e1 e2 manual

You possess an (or a rebadged equivalent from a Gateway/Dell/HP system using the Intel 845E chipset). It is a legacy Pentium 4 motherboard designed for Windows 98/XP/2000. While it lacks modern features like SATA or PCIe, it is highly reliable for retro-computing builds. The codes are typically listed in Appendix A: