Facing TV Problems? Ask a TV Technician.
When you replace your main board, you take it out of engineering mode by pressing the power key or the ok key in the center of your arrow keys on your LG's remote. That should clear the unit. If not, try the power button on the TV set - that's the alternate if the remote doesn't clear it.
If you have not replaced the main board, inform me please.
Ok, so you turned the TV on in the morning and got that display showing. That usually points to a defective main or the tcon, depending on what your TV is doing. If it's staying on an all white screen and not cycling different colors, then it's the main. If it cycles colors, then the Tcoin isn't receiving the picture signal