Hi MNOIM, Thank you for sharing your experience with your U7900F TV. If your screen goes black or you're intermittently losing picture and no external device is connected, please try the following: 1. Check for signs of power. Press the Home button on your remote - if the menu appears, the TV is powered on and the issue may be with the signal or source. 2. Confirm the red standby light is functioning. When off, the standby light should be on. When the TV is in use, the light should turn off. If the standby light is off at all times, your TV may not be receiving power. 3. Run a Picture Test to rule out hardware issues: Home > Settings > Support > Device Care > Self Diagnosis > Picture Test 4. Update your TV's firmware if the screen stays on long enough: Settings > Support > Software Update > Update Now 5. Factory Reset if the issue persists: Settings > General & Privacy > Reset > Enter PIN (default: 0000) If the screen remains black and you’re unable to access any menu, the TV may require service. Please give us a call at 1-800-SAMSUNG (8AM – 9PM EST Mon – Fri, 8AM – 6PM Sat – Sun), or visit the ‘Support’ section on our website to chat live with an agent. ~ Samsung Advisor

Hi Not happy, We appreciate your feedback regarding your U7900FD TV’s performance. If you're experiencing freezing or lag in general response time, please try the following steps: 1. Check for firmware updates – Keeping your TV up to date can resolve many performance issues: Home > left directional key > Settings > Support > Software Update > Update Now 2. Run Device Care – This tool checks system memory, frees up cached data, and closes background apps that could be slowing things down: Home > left directional key > Settings > Support > Device Care > Start Device Care 3. Cold boot your TV – With the TV powered on, press and hold the Power button on your remote for 5+ seconds until the TV restarts. This helps refresh the system. If you're still noticing performance snags after these steps, please contact Samsung Support at 1-800-SAMSUNG (8AM – 9PM EST Mon – Fri, 8AM – 6PM Sat – Sun). You can also connect with a LiveChat agent via the ‘Support’ link on our website. ~ Samsung Advisor