LinkMejor 1 Set CH341A Programmer 3.3-5V Compatible with EEPROM 24 25 Series

I. Unrecognized Chip

1. Check for loose connections and correct pin assignments.

2. To avoid USB 3.0 compatibility issues with your computer, please use a USB 2.0 interface instead.

3. Insufficient power supply to the computer's front USB port, or the USB cable only supports charging and not data transfer.

4. 12C speed is too high; reduce the clock frequency (high frequency may cause signal instability).

II. Unable to Read/Write

1. Reinstall the driver or try a different programming software version.

2. Re-erase the chip (residual data may cause write errors).

3. The data written exceeds the chip's capacity (the overwrite operation will fail). 4. Reinstall the driver or change the programming software version.

5. Incorrect chip model selected, incorrect interface mode (12C/SPI confusion)

III. Device fails to boot after firmware flashing

1. Replace with matching firmware and perform an "Erase > Flash Verify" operation at a low speed of 100kHz to confirm data consistency.

2. Use a multimeter to check if the chip's VCC-GND are short-circuited.

3. Remove the chip's read/write protection (some EEPROM chips have a write protection pin that needs to be grounded to unlock).

4. Overwrite the original data with backup data and restore factory settings.