Broadlink SP4 Smart Plug Resolving Firmware Loop After Manual Reset

Introduction

The Broadlink SP4 is a compact 4‑outlet smart plug that many homeowners rely on for scheduling lights, appliances, and other devices. Its convenience is rooted in the ability to control each outlet remotely through the Broadlink app or third‑party platforms such as Home Assistant. However, a recurring issue for some users is a firmware loop that appears after a manual reset. The plug repeatedly boots into a status where the firmware cannot finish loading, resulting in an offline device that refuses to accept new settings.

This guide walks you through diagnosing the loop, performing a clean manual reset, re‑flashing the firmware, and confirming that the SP4 returns to stable operation. The steps are written for users with basic technical confidence and do not require specialized equipment beyond a smartphone, a computer with USB‑to‑serial capability (optional), and the Broadlink app.

Understanding the Firmware Loop

When the SP4 starts, its bootloader loads the firmware from internal flash memory. If the firmware image is corrupted, incomplete, or mismatched with the hardware revision, the bootloader cannot hand control over to the operating system. In this state the plug may cycle through the following symptoms:

• The LED indicator flashes rapidly in a pattern different from normal pairing mode.
• The Broadlink app repeatedly shows “Device offline” even after the plug appears powered.
• Attempts to add the plug again trigger the same pairing sequence but never complete.

The root causes typically fall into three categories:

1. Interrupted OTA update – A network interruption during an over‑the‑air firmware upgrade can leave a partially written image.
2. Mismatched firmware version – Using a firmware file intended for a different SP4 hardware revision (e.g., v1 vs v2) can cause incompatibility.
3. Flash wear or hardware defect – Repeated flashing can degrade NAND cells, making the memory unable to reliably store the image.

Recognizing that the device is stuck in this loop is the first step toward recovery.

Preparing for a Successful Reset

Before you begin, gather the following items:

• The Broadlink SP4 plug and its power cable.
• A stable Wi‑Fi network (2.4 GHz) with a known SSID and password.
• A smartphone with the latest Broadlink app installed (iOS 15+ or Android 10+).
• A computer with internet access to download the correct firmware file from the Broadlink support portal.
• Optional: a USB‑to‑TTL serial adapter if you want to verify flash contents directly.

Create a clean workspace where you can easily access the plug’s reset button (a small hole on the side near the power cord). Have a paper towel ready in case you need to press the button firmly.

Back‑up Existing Configurations

If the plug is still partially reachable on the network, open the Broadlink app and export any device groups or schedules that involve the SP4. While the firmware loop typically makes the device non‑responsive, a quick backup may save you time later.

Verify Firmware Compatibility

Visit the official Broadlink download page and locate the firmware version labeled for SP4 – Model SP4‑X (replace X with your hardware revision). Download the .bin file and note its version number. Do not use community‑built or third‑party firmware unless you are comfortable with the attendant risk.

Manual Reset Procedure

The manual reset restores the SP4 to its factory settings and forces it into Wi‑Fi pairing mode. Follow these steps precisely:

1. Power off the plug – Unplug the power cable from the outlet. Wait at least five seconds.
2. Locate the reset pin – The reset button is a recessed pinhole on the side panel. You will need a paperclip or a similar thin object.
3. Press and hold – Insert the paperclip into the pinhole and press firmly while you plug the power cable back in. Keep the button pressed for 10 seconds. The LED should change from solid white to a rapid orange‑white flash, indicating entry into reset mode.
4. Release the button – After the LED pattern changes, let go of the pin. The plug will restart and remain in pairing mode for about 2 minutes.

If the LED does not flash as described, repeat the process. In rare cases the reset mechanism may be stuck due to a hardware fault; gently tap the reset button with the paperclip to ensure proper contact.

Re‑flashing the Firmware

Once the plug is in pairing mode, you can either let the Broadlink app auto‑update it or manually flash the firmware using a PC. The manual method gives you full control and helps avoid the loop re‑occurring.

Using the Broadlink App

1. Open the app and tap the + icon to add a new device.
2. Select Smart Plug → SP4 from the list.
3. Follow the on‑screen instructions to connect the plug to your Wi‑Fi network.
4. If the app detects that the firmware is outdated, it will prompt an OTA update. Confirm and allow the update to complete without interruption (keep the phone near the plug and avoid Wi‑Fi changes).

Manual Flash via PC (Advanced)

If the OTA approach fails, use this method:

1. Install a flashing tool – Download the open‑source “Tuya‑Convert” or “Broadlink Firmware Tool” compatible with your OS.
2. Connect the PC to the same Wi‑Fi – Ensure the computer shares the 2.4 GHz network with the plug.
3. Put the plug in listening mode – With the plug still flashing orange‑white, run the tool’s discovery command (broadlink-discover). The tool should list the device’s IP address.
4. Upload the firmware – Execute the flash command, pointing to the .bin file you downloaded earlier. Example:

   broadlink-flash --ip 192.168.1.45 --file SP4_vX.Y.Z.bin
   

5. Wait for completion – The tool will display progress percentages. Do not power off the plug until the process reports 100 % and the LED returns to solid white.

If you have a USB‑to‑TTL adapter, you can connect to the plug’s serial pins (available on the bottom of the unit after removing the cover) and run a low‑level flash verification script. This step is optional and primarily for debugging stubborn cases.

Verifying Stable Operation

After the firmware flash finishes, the plug will reboot automatically. Perform these checks:

• LED status – The LED should stay solid white for a few seconds, then transition to a slow pulsing green, indicating normal standby.
• App discovery – Open the Broadlink app and look for the SP4 under “My Devices”. It should appear online and show the correct firmware version.
• Control test – Tap the toggle for each of the four outlets to turn them on and off. Verify that physical devices connected to each outlet respond accordingly.
• Network stability – Ping the plug’s IP address from a computer (ping 192.168.1.45) for a minute. Consistent replies with low latency indicate a healthy Wi‑Fi link.

If any of these steps fail, repeat the manual reset and flash sequence. Occasionally the plug may need a brief power‑cycle after flashing to clear residual cache.

Common Pitfalls and How to Avoid Them

By anticipating these issues, you can keep the recovery process smooth and avoid entering the loop again.

Advanced Tips for Power Users

• Batch flashing – If you manage multiple SP4 units, script the flashing tool to iterate over a list of IP addresses. This saves time in larger deployments.
• Custom firmware – Some enthusiasts install home‑brew firmware that adds MQTT support for tighter Home Assistant integration. Proceed only if you have backed up the original firmware and understand the risks.
• Static IP assignment – Assign a fixed IP to the plug via your router’s DHCP reservation table. A static address prevents the plug from disappearing after reboots, simplifying troubleshooting.

When to Seek Professional Support

Even with careful handling, hardware defects can arise. Consider contacting Broadlink customer service if you encounter any of the following:

• The plug fails to power on after multiple reset attempts.
• The LED remains off or shows a constant amber color.
• Repeated firmware flashing does not change the device’s behavior.

Provide them with the serial number (usually printed on the bottom of the plug) and a brief log of the steps you have taken. Most manufacturers honor a one‑year warranty for defects unrelated to user modification.

Conclusion

A firmware loop on the Broadlink SP4 can be frustrating, but it is a solvable problem with a systematic approach. By understanding why the loop occurs, executing a precise manual reset, and flashing the correct firmware version, you restore the plug to reliable operation. Regularly updating the firmware through the official app, keeping the device on a stable 2.4 GHz network, and performing occasional health checks will help prevent future loops.

With the SP4 back online, you can once again enjoy seamless control of your home’s electrical devices, integrate them into automations, and make the most of your smart home ecosystem.