Sony XBR-55X900F 4x red lights flashing after dark screen

@lesterstoker the 4 blink error code for your TV is a LED driver failure/LED voltage protection [LD_ERR] error. Two things are common. Your LED driver board or your backlight strips. My money is on the backlight strips, which is fairly common for Sony TV's

Here are the flowcharts for the LED driver board 4 Blink Error Code

The problem here is that your TV uses a circuit which knows when your backlight strips are weak/filed and will give you this code. There might be a way of bypassing that but we would need to see the boards and their connectors (with legend). Sometimes bypass the error detect will work. Post some pictures of your boards with your question. Adding images to an existing question

Here is how you would need to change the backlight strips Not the identical model but identical work.

Expensive? No. PITA? Definitely.