A Samsung TV that continuously turns off and on by itself is experiencing a "power cycling" issue. This can be caused by anything from a simple software glitch or an external device sending conflicting signals to a failing internal component . Because the causes range from simple settings to complex hardware failures, you should troubleshoot in a specific order.
The following methods are arranged from the simplest software fixes to more advanced hardware diagnostics. Only proceed to hardware disassembly if you are comfortable with electronics and your TV is out of warranty.
### ????️ Method 1: The Basic Software and Settings Fixes
Before suspecting a serious hardware fault, rule out software and configuration issues.
**1. Perform a "True" Power Cycle (Not Just Unplugging)**
A standard restart often doesn't clear the TV's residual memory. To perform a full power drain:
- Turn off the TV and **unplug it from the wall**.
- **Wait 5 full minutes** (not 60 seconds) to let the capacitors discharge .
- While unplugged, **press and hold the physical power button** on the TV (not the remote) for 30 seconds to drain any leftover charge .
- Plug the TV back directly into a wall outlet (avoid power strips for this test) and turn it on .
**2. Check for External Interference (HDMI-CEC / Anynet+)**
The most common cause of random power cycling is **HDMI-CEC**, which Samsung calls **Anynet+**. This feature allows devices like your PlayStation, Xbox, or soundbar to control the TV’s power. However, buggy signals often create an on-off loop .
- **Navigate to:** `Settings > Connection > External Device Manager > Anynet+ (HDMI-CEC)` and turn it **Off** .
- If you need CEC for audio, try disconnecting devices one by one to find the culprit. The **Amazon Fire Stick, PS5, and Sonos soundbars** are frequently reported to cause this issue .
**3. Disable "Power On with Mobile" and Timers**
- **Network Wake:** Go to `Settings > Connection > Network > Expert Settings` and turn off **Power On with Mobile** to prevent phones or apps on your Wi-Fi from triggering the TV .
- **Timers:** Go to `Settings > General & Privacy > System Manager > Time` and ensure **Sleep Timer** and **Off Timer** are set to **Off** .
- **Energy Saving:** Disable **Auto Power Off** and **Eco Sensor** found in `General & Privacy > Power and Energy Saving` .
### ???? Method 2: Using the Hidden "Event Log"
For 2019 models and newer, Samsung includes a diagnostic tool that tells you *why* the TV turned on or off .
- **Navigate to:** `Settings > Support > About TV > Event Logs` .
- **Interpretation:**
- *"CEC Command"*: Confirms Method 1 (HDMI-CEC) is the issue.
- *"SmartThings" or "WOL"*: A device on your network is waking the TV (Method 1).
- *"Sensor"*: The ambient light sensor is malfunctioning or detecting movement (turn off Eco Sensor) .
### ???? Method 3: The DIY Hardware Diagnostic
If the software fixes fail and the TV continues cycling, the issue is likely internal. **Warning:** Opening your TV voids the warranty and carries a risk of electric shock or further damage. Only proceed if comfortable.
**The "Backlight Test" (Isolating the Screen vs. Boards)**
This test determines if the power cycling is caused by a faulty mainboard or a shorted screen .
1. Unplug the TV and remove the back cover.
2. **Disconnect the cable** between the **Power Board** and the **Main Board** (the board where HDMI plugs in) .
3. Plug the TV back in.
- **Scenario A (Backlights stay ON & steady):** The power supply and LED backlights are likely fine. The issue is probably the **Main Board** .
- **Scenario B (Backlights blink or turn OFF):** There is a short in the **Power Board** or the **LED Backlight array** .
**The "Screen Short" Fix (Taping the Ribbon Cable)**
If Scenario B occurs, the problem is often a short inside the screen's edge buffer boards. A temporary fix involves blocking specific pins on the ribbon cables:
1. Locate the thin ribbon cables running from the mainboard to the top or bottom of the screen.
2. Disconnect one side at a time and plug the TV in. If the TV stays on when one side is disconnected, the short is on that side .
3. Place small strips of **electrical tape** over the first 4-6 pins on the ribbon cable for the faulty side and reconnect it. This often blocks the short circuit and stops the cycling, though you may lose slight picture quality on that edge .
### ???? When to Call a Professional
While the "Tape Trick" can buy time, it is not a permanent solution. You should stop troubleshooting and contact Samsung Support or a local repair shop if:
- The **Event Log** shows errors unrelated to CEC or timers.
- The power cycling started immediately after a **power outage or lightning storm** (likely damaged the power board).
- You hear a **buzzing** sound accompanied by the flashing logo.
- You are uncomfortable opening the electronic device .
If your TV is relatively new and still under warranty, do not open it—contact Samsung directly for a replacement or service appointment .