Hey everyone,
I’m hoping someone here can help me figure out what’s going on with my 48” LG C1 OLED. The TV was working perfectly and then, out of nowhere, it just shut off completely—no warning, no flicker, just instant black screen. Since then, I haven’t been able to get it to turn on at all.
When I press the power button, the standby LED does respond, so it’s at least getting some power. I also hear a double-click from the power supply area (sounds like a relay clicking on and then off), but there’s no LG chime, no picture, and no backlight. If I disconnect the T-con board’s power connector, the clicking stops completely. If I disconnect just the T-con data cable (EAD63285709), the TV actually boots up—I hear the LG chime and get a 3-blink error code. If both the T-con power and data are disconnected, I get no clicking and no chime.
I haven’t seen any obvious signs of damage like blown capacitors or burn marks on any of the boards. I’ve tried swapping and removing cables to isolate the issue (as above), but I haven’t replaced any boards yet. I do have a multimeter and am comfortable using it, but I’m not totally sure which pins I should be checking for the 12V and 21V rails on the power supply or T-con connectors.
Does this sound more like a T-con board failure, a power supply issue, or (worst case scenario) a shorted panel? What voltages should I be checking with my multimeter, and where exactly? Is there a way to definitively tell if the panel is the culprit without just throwing parts at the problem? Any other diagnostic steps I should try before I start ordering boards?
I added a video of me trying to turn it on with everything connected and with the 12V connection unplugged.
Any advice or experience with similar LG OLED issues would be hugely appreciated.


LG C1 48 suddenly shut off