SONY XR-77A80J Times

Main Logic Board

On the XR series, the 4-blink code often points to an internal communication error between the System-on-Chip (SoC) and the panel's timing hardware. If the Main Board cannot verify the T-Con's status or the 12V supply is compromised by a board-level component failure, the TV enters a protection loop. Replacing the Main Board restores the digital handshaking required for panel initialization.

T-Con Board

The Timing Controller (T-Con) is the traditional source of the 4-blink error code in Sony diagnostic architecture. A short circuit in the T-Con's local DC-DC converter or a failure in its processor prevents the panel from receiving scan data. This board is the physical interface between the main logic and the OLED panel glass.

LVDS/Ribbon Cable Kit

Physical degradation or thermal stress on the high-density ribbon cables connecting the Main Board to the T-Con can cause intermittent data loss. When the self-diagnostic circuit detects a signal integrity failure on these lanes, it defaults to a 4-blink protection mode to prevent panel damage.