Hardware⏱️ 3 min read📅 2026-06-15

How to Fix 0x05 Error – Difference between S.M.A.R.T. error 0x05 (Reallocated sector) and 0xC6 (Uncorrectable sector)

Understanding S.M.A.R.T. errors on external hard drives, specifically the difference between 0x05 (Reallocated sector) and 0xC6 (Uncorrectable sector).

Quick Answer: The drive may not have reallocated the sector due to its location or data integrity, potentially causing issues with reading/writing operations.

A high number of S.M.A.R.T. error codes, such as 0xC5 (Pending sectors) and 0xC6 (Uncorrectable sector), can be frustrating for users who rely on their external hard drives for data storage. These errors often indicate underlying issues with the drive's health and performance.

In this guide, we will explore the differences between S.M.A.R.T. error codes 0x05 (Reallocated sector) and 0xC6 (Uncorrectable sector), and provide troubleshooting steps to help resolve these issues.

🔍 Why This Happens

  • The reallocated sector count remaining at 0 despite a high number of pending sectors indicates that the drive's firmware may not be properly handling the errors. This could be due to a hardware issue, such as a faulty read/write head or a damaged disk surface.
  • Another possible cause is a software issue, such as a misconfigured disk management system or an incompatible operating system. In this case, the drive's firmware may not be able to reassign the bad sectors correctly.

✅ Best Solutions to Fix It

Reformatting and Reinitializing the Drive

  1. Step 1: Locate the device manager on your computer and expand the 'Disk drives' section.
  2. Step 2: Right-click on the external hard drive and select 'Properties'. Click on the 'Settings' tab and then click on the 'Erase data from disk' button.
  3. Step 3: Confirm that you want to erase all data on the drive. Once complete, let the drive format and reinitialize. This will reset the drive's firmware and potentially resolve the error issues.

Checking for Firmware Updates

  1. Step 1: Visit the manufacturer's website and search for firmware updates for your external hard drive model.
  2. Step 2: Download and install the latest firmware update. Follow the on-screen instructions to complete the update process.
  3. Step 3: After updating the firmware, restart your computer and check if the error issues have resolved.

✨ Wrapping Up

If you have followed these steps and the error issues persist, it may be necessary to replace the external hard drive. In some cases, a faulty read/write head or damaged disk surface can only be repaired by replacing the entire drive. However, by following these troubleshooting steps, you should be able to resolve most S.M.A.R.T. error issues related to 0x05 (Reallocated sector) and 0xC6 (Uncorrectable sector).

Did this fix your problem?

If not, try searching for specific error codes.

🔍 Search Error Database

❓ Frequently Asked Questions