Have TV Questions? Ask a TV Technician
Hi, I'm Nathan.Sorry to hear that you're having trouble, but I'll do my best to help you. Please give me a few moments to review your details here.
It sounds like you may be on the wrong input by accident.
Take the LG tv remote, and press the SOURCE or INPUT button, repeatedly, to cycle through the different options. On one of them (usually hdmi1 or hdmi2) you should hit on the signal for your cable box again.
If you get stuck, I can guide you through but need a bit more detail - recheck the tv model as what you sent looks more like a serial or the remote, and look at the back of the tv to see specifically where the cord from the box is plugged in.