When using the flash assistant to flash the iPhone 4, an apple logo set error appears, indicating that there is an error when flashing Apple's logo information.

Solution: Use itunes to flash the phone. Steps to flash the phone:

1. Turn off the iPhone, use the data cable to connect to the computer, and open the computer's iTunes software.

2. Press and hold the Power key for 2 seconds.

3. Without releasing the Power button, press the Home button for 10 seconds to force shutdown.

4. Without releasing the Home button, tap the Power button once. Hold the Home button for about 15 seconds. The phone screen will display the icon message of connecting to Itunes and enter DFU mode.

5. The computer has sound and text messages prompting that new hardware has been discovered, and iTunes prompts that there is an iPhone that needs to be restored. Click Restore and iTunes will automatically download the latest firmware to update and flash the device.