This chapter focuses on advanced faults of Iphone OLED screens, such as screen burn-in, green lines, vertical/horizontal stripes, and dead pixels. It explains the working principle of OLED panels and the causes of common faults, including IC damage, flex cable oxidation, and panel internal short circuits. Content includes flex cable repair, IC replacement, and screen calibration techniques. It also covers the use of professional equipment like screen testers to diagnose hidden OLED faults. Learners will master advanced OLED repair skills to handle complex screen issues.