Troubleshooting - The brightness on the television randomly changes is this adjustable.

If the brightness on your TV changes automatically (randomly brightens or dims), you may need to change one or more of the television's default settings. Settings are:


  • C.A.T.S.
  • Automatic gain control (AGC)

C.A.T.S is an Energy saving function that detects the brightness of the room and automatically adjusts the screen brightness to match. It maintains easy-to-watch images while reducing power consumption. The default setting for "STANDARD" picture mode for C.A.T.S is ON. In all other picture modes, the default setting for C.A.T.S is OFF. The changes in brightness can look like flickering. For assistance on minimizing this, set the C.A.T.S. setting to OFF. To turn off C.A.T.S., follow these steps:


  1. Press the [MENU] button.
  2. Select "Picture" or "video". Press [OK].
  3. Use "Down Arrow" (▼) to select "C.A.T.S.", and Press [OK].
  4. Use "Down Arrow" (▼) to select "OFF", and Press [OK].


On screen display menu varies by model.


AGC (Automatic Gain Control) automatically controls the brightness of excessively dark or bright signals to maintain accurate reproduction of details. The AGC level adjustment is available in CUSTOM and CINEMA picture modes (the default setting for AGC is "7" in CUSTOM mode). This level provides good brightness control for gaming content but can look like flickering for other sources. To correct this issue, set the AGC level to "0". (The default setting for AGC is "0" in CINEMA mode).


  1. Press the [MENU] button.
  2. "Picture" section will be selected by default. Press [OK].
  3. Use "Down Arrow" (▼) to select "Pro Settings" (page 2), and Press [OK].
    • For model TC-55GX800 and TC-65GX800 Confirm that Contrast A.I. is set to Custom and not auto or Off in order to adjust AGC setting.
  4. Use "Down Arrow" (▼) to select "AGC", and Press [OK].
  5. Use "Left Arrow" (◄) to adjust to "0", and Press [OK].

If the flickering continues after setting C.A.T.S. to OFF, and setting the AGC level to 0, the signal may be weak or unstable, test the TV on a different source. Some picture content that includes fast brightness changes can create a flash on-screen. One example of this is when a strobe light is used during a broadcasted hockey game.


If the flickering continues after you have changed the settings above and tested a different source, your television may require service.

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