Intel Desktop Board 01 21 B6 E1 E2 Er -

Check with a multimeter on the POST code pins (usually 4 pins labeled “Port 80” diagnostic header):

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.

Let’s dissect each alphanumeric value. intel desktop board 01 21 b6 e1 e2 er

Given the age of boards displaying these codes (most are LGA775, DDR2, or early DDR3), you face a value decision:

Final recommendation: If your board hangs consistently at b6 or E1 after removing all USB and RAM, the chipset is degraded. Data recovery is not at risk; only the board’s ability to POST. In that case, migrate your CPU, RAM, and drives to a compatible used board. Check with a multimeter on the POST code

Intel Desktop Boards from 2004–2007 were affected by the capacitor plague. Look for electrolytic capacitors (small cylindrical cans) near the CPU and RAM slots. If the tops are bulging or have brown crust, the board is dying. Replacing these capacitors requires soldering skills but can save the board.

| Code | Meaning (from Intel POST Code Reference) | |------|--------------------------------------------| | 01 | Processor internal test – starting CPU initialization. If stuck, indicates CPU or power issue. | | 21 | OEM memory detection / initial memory sizing. Very common early step. | | b6 | Not standard Intel. Likely a vendor-specific or misread code. In AMI BIOS (used on some Intel boards), b6 is “Clean-up of NVRAM.” | | e1 | Not standard. Possibly “E1” meaning “Runtime APIC initialization” or in some boards, “Error in SMM (System Management Mode).” | | e2 | Could be “E2” – “Initialize multi-processor AP” or in some cases “Invalid password” (rare). | | er | Most likely an error display on a 2-character debug LED – meaning “ER” = General Error / Halt. Could be “E2” misread as “Er.” | Your board is not showing all these codes at once

Important: Intel’s official POST code list for boards like the Intel DQ67SW includes E1 and E2 as final halt codes when BIOS detects a fatal error (e.g., incompatible CPU, corrupted BIOS, missing VGA).

Status: Early memory detection
Meaning: Code 21 indicates the BIOS is waking up the memory controller (traditionally on the Northbridge chipset) and beginning to sense if RAM modules are present. This is before SPD reading or timing training.

If stuck at 21: