Why is the RCA LED55C55R120Q TV Screen Only Showing the Backlight?

Thanks for the clarification regarding the Frame Rate Control (FRC) board. I’ll edit the post and update. I just finished testing voltages pwr on and off on the Power Supply board and looks all in spec. I’m guessing the T-Con board is behind the metal plate before the boards related to the LCD Screen. I’ll remove, inspect, photograph and report back.

Your second picture of the T-con board shows the place where the inductor fell off. There does not appear to be any damage to the board. Try resoldering the part back on. Match the placement with the profile on the board.

I resoldered the inductor in place and the LCD Screen is working now... though I noticed some ghosting at first of the "NO SIGNAL" box for a few seconds that goes away as it is moving.

The center of the screen appears to be a darker blue... though I didn't notice anything worse with the "NO SIGNAL" box as it moved through that region and the backlights seem to be as intense.

I'm wondering about Q101 and the traces there. That area looks like something circular ground against the board and I soldered two traces that looked like they were ground/cut. I didn't replace the Q101 transistor and I guess that will improve the image quality issues I'm observing.

I'll have to find a schematic or determine what the transistor is to restore better quality I'm thinking.

The LCD Screen Is working now! Thank you sir!

I thought that may have been some residue from a cotton swab or cloth. Any marking on the transistor at all?

I see also where the three sheet metal screws were used instead of the base mount screw in that same location... that might have been what screwed into the T-Con board and caused the circular pattern and broke the inductor off. I'm not sure how the circular pattern was made so large though compared to the hole diameter of the base mount plate unless the tip was offset at an angle though maybe a smaller diameter wood screw was used crooked or something first. Doesn't seem to make sense with the three sheet metal screws I found with loosely holding the base on.

I have another free LED55C55R120Q with the same symptoms and am going to measure that transistor and see if maybe I have a similar transistor on another video card or some salvage board.