Chosen Solution
Hello, I have a Sony XBR-55X850C and I have no backlight, no display but I do have sound. When I first turned the tv on it flashed 6 red LEDs. Looked up the code and it said it could be the backlights or the main or power supply board. I opened the tv up and seen that the main board was getting voltage for a few seconds then shutting off. I disconnected the T-Con board, the backlights came on. It was displaying a series of colours. I turned the tv off and plugged the T-Con board back in. When I turned it on the LED say there bottom was flashing between Orange and Green, indicating it needs a firmware update. Followed the instructions on the Sony website for updating with a memory stick. It does say to follow the instructions on the screen (can’t do as there is no display) . If I press the power button I get a white LED to come on, still no display or backlights. The 6 red LEDs have not come on since. I tested the backlights and they still work. Unplugging the T-Con board doesn’t display the colours either. Below are the voltages I’m getting with the power on. Backlight 1+2 68V 1- NC - No Pin 2 - DC_dimmer 0V 3- BL_ON 0V 4 - PWM_DIMMER 0V 5 - STBY_3.3 3.47V 6 - BLINKING 0V 7 - AC_OFF_DET 3.48V 8 - BL_ERR 2.5V 9- POWER_ON 3.4V 10- GND - n/a 11- GND - n/a 12- GND - n/a 13- REG12V 12.6V 14- REG12V 12.6V 15- REG12V 12.6V 16- REG12V 12.6V 17- REG12V NO PIN 18- REG12V 12.6V 19 - GND n/a 20 - GND n/a 21 - GND n/a 22 GND n/a 23 GND n/a 24- TCON_ON 0V 25- TCON_VCC_12 0V 26- TCON_VCC_12 0V 27- TCON_VCC_12 0V 28- TCON_VCC_12 NO PIN
Tyler Saboe the backlight voltage seems a bit low. you’ve tried shining a flashlight beam at an angle to see if you can make out silhouettes etc.? If you do not then the issue is more likely the t-con board , main board and power board/backlight array last. Follow the flowsheet to see what you can find out.
FWIW, I re-tried the firmware installation and my TV came back from the flashing green and orange/amber light. and no picture/no backlight but with sound. I tried it when I first got the flashing lights, but there was no change. Then looking at the voltages, I wasn’t getting correct standby voltages(there was always full power going to all the boards regardless of whether indicator light was on/off) - indicating the TV was “doing something” else. So I retried with the same USB stick and it just worked the second time. Still need to replace the T-Con board to resolve the flicker, but I do have a picture, and I didn’t have to replace the main-board or backlight.
