Bravia XR-75x95J No Picture but has Sound (No red light blinking)

Issue: My XR-75X95J Power-ON AFTER plugging the TV into wall socket the TV will display SONY logo and then goes fully black.

Notes: A) The remote can still power on/off the TV.

            B) Pressing the up/down/select of the remote causes the normal sound to happen.

             C) There are no cables connected to the TV except for the power cable.

             D) We attempted to connect a PS4 for troubleshooting to the HDMI port and tried to get the TV to acknowledge a separate input source, but it did not.  All troubleshooting performed with nothing plugged into the TV.

E) Turning the TV OFF/ON while connected to the wall socket after the initial POWER-ON from plugging the TV into the socket results in no SONY logo appearing (the screen remains black).

F) There are no blinking red lights. The normal white light appears during the POWER-ON phase.

Troubleshooting steps performed:

1) We power  cycled the TV: (waited 2 minutes, 2 hours, 8 hours) and then tried plugging in the TV.

2) We power cycled the TV with soft reset: after disconnecting from the wall (waiting 2 minutes, 2 hours) and then holding down the (single) power button on the TV for 60 seconds with the power cord UNPLUGGED, we then plugged the power cord back in without holding down the power button on the TV.

3) We tried to factory reset the TV by unplugging the power cable, waiting (2 minutes, 2 hours, 8 hours) and then holding down the TV power button while simultaneously plugging the power cord back into the wall.  This produces the same SONY logo and then sometimes shows a multi-colored hollow circle on the screen with the word "Erasing" after which the TV goes black.  Sometimes the TV power cycles twice during this sequence and sometimes it does not.  The end result is the same, the TV only shows the SONY logo and then goes to a full black screen.

4) We downloaded the firmware from the SONY website for this model: v6.7612 as well as v6.8092.  We formatted a USB stick as FAT32/32 and named the USB stick "SONY UPDATE".  We then loaded the v6.7612 files (.zip and .dep) that we extracted from the SONY zip and performed the steps listed on the SONY website (https://www.sony.com/electronics/support...) for a firmware update.  This was attempted multiple times with the screen never displaying anything.  On one of the attempts the pilot light on the TV DID blink white on/off for several seconds but on that attempt we left it for 12 hours and the results were the same as all previous troubleshooting steps.  On all other attempts there was no blinking/pairing indicator on the pilot light.  After each failed attempt we also tried a power cycle and then a factory reset.  Note that the files were correctly placed in the root directory of the flash drive, and after each attempt we completely deleted the flash drive and reformatted it before once again copying over the 2 files provided in the SONY zip.

5) We repeated step #4 with the v6.8092 firmware files downloaded from SONY.

6) We repeated steps #4 and #5 using a USB stick formatted for FAT32/16.

7) We once again tried a power cycle, soft reset and factory reset.

8) Periodically during the above steps we used a flashlight to look at the TV once it went black after the SONY logo went away.  There was never a faint picture showing, it was completely black.

9) We opened up the back of the TV, checked capacitors on all boards and found no bulging.

10) We disconnected all cables on the back of the board and checked for oxidation (everything looked shiny/clean with gold/silver connectors). We blew down everything and the boards while unplugged using compressed air.

• The POWER-ON following the above produced a working TV that was at the Factory-default screen. We went through the initialization process, got to the Home screen and updated the software using the on-screen Settings selection process. The TV successfully powered ON and OFF several times using the remote. Apps worked.
• To verify everything was good before putting the back on, I turned OFF the TV using the remote and then unplugged it from the wall overnight.
• The following morning the situation was back to square 1: Initial Power-ON showed the SONY logo and then screen goes completely black. No flashing red light (just normal white light acknowledging Power-ON). Sound working (beep selecting things etc).

I have the repair manual but it doesn't seem to have diagrams for any board other than the mainboard and I'm trying to get to 'next steps' in the troubleshooting process. I'm having trouble telling what each of the cables is that connects the boards (that are not Pin cables) as well as figuring out what to check based on Page 45 of the Manual (No Picture flow diagram).

What I know for certain is that it's not a backlight issue. It seems like it might be related to the cables OR could be related to the Mainboard, T-con or 4th board that isn't the the above or Powerboard (don't know what its called).

Any help would be much appreciated!