"Incompatible phone" prompt during pairing on phone settings page.

Tap the "Disconnect" button on the app's home screen to access your Bluetooth devices. Look for and connect to "T001 Plus".

Cannot find device during Bluetooth pairing.

After double-clicking Feed, search for the device on the app's Bluetooth page within 30 seconds. Before that, ensure the Bluetooth key is not plugged into the computer. Also, enable Bluetooth permission for 4Barcode in your phone's settings.

Driver installed but printer does not print

Check the device list. If two 'T001' printer devices appear, uninstall all drivers and reinstall.

Open the computer's print settings interface, select 'T001 Plus' to print.

Printed image does not match paper size (too small, misaligned, missing)

Calibrate paper: Press and hold the FEED button for 3-6 seconds until the red indicator flashes, then release.

Open the computer's print settings interface-> Paper Size, select the size type that matches your label paper.

Missing pixels, broken lines, white spots in solid areas

Clean the print head regularly: Gently wipe the print head (smooth metal strip) in one direction with a cotton swab dipped in rubbing Alcohol alcohol (70% or higher concentration).