Since you searched for all six codes together, you are likely experiencing one of three failure patterns:
Intel desktop boards use beep codes or LED POST codes (on high-end boards).
01 21 b6 e1 e2 could represent diagnostic LEDs (often in hex). ER might stand for “Error.”
Developed content:
Diagnostic LED Code Interpretation (Intel Desktop Board)
If your Intel desktop board displays the code sequence
01-21-b6-e1-e2followed byERon the POST code reader or debug LEDs: intel desktop board 01 21 b6 e1 e2 erPossible causes:
Fix steps:
| POST Code | Phase | Most Likely Culprit | Quick Fix | |-----------|--------------------------------|----------------------------------------------|--------------------------------------------| | 01 | CPU microcode & cache init | Dead CPU, missing 4-pin, bent pins | Reseat CPU, check PSU cable | | 21 | RAM presence detection | No RAM, wrong slot, incompatible DIMM | Use one stick in A1, clear CMOS | | b6 | USB controller init | Shorted USB device or front-panel header | Disconnect all USB, remove headers | | E1 | SMBus (SPD & sensors) | Corrupt CMOS battery, bad RAM SPD | Replace battery, test RAM one by one | | E2 | PCI/PCIe bus enumeration | Faulty GPU, dead onboard NIC | Remove all cards, try legacy PCI GPU | | ER | Handoff to bootloader (success) | No OS, wrong SATA mode, corrupt boot sector | Check boot order, enable IDE/Compatibility |
Your board is not showing all these codes at once. It is cycling through POST phases. Typically, a healthy boot will rapidly count from 01 up to FF or ER (which often means "Execute Ready" or "Error"). If the boot halts at a specific code, that is where the problem lies. Since you searched for all six codes together,
Let’s dissect each alphanumeric value.