A:Answer Hi,
We appreciate you sharing the issues you’re experiencing when connecting your TU690T TV to your cable box. Please go to the Connection Guide for details: Source > Connection Guide.
Make sure that your external device is connected securely and turned on. Move to Sources to switch to other input sources: Source > Sources.
Using HDMI Troubleshooting, you can check the connection to the HDMI cable and external devices (it takes approx. 2 minutes). Source > Connection Guide > Video Device > HDMI Troubleshooting.
Also, please check the broadcast signals or the network that is connected to your cable box.
For further assistance, please know we’re here to help. Call us at 1-800-SAMSUNG, 8 AM - 12 AM EST, seven days a week. Or visit us on the Samsung website and click on the ‘Support’ link for:
1) LiveChat
2) Manuals, Software, & Warranty Info
~ Samsung Advisor