A Roku device may keep restarting repeatedly due to several common issues:

• Power supply problems: Using a wrong or insufficient power source, such as powering through a TV USB port instead of a wall adapter, or a faulty power adapter can cause reboot loops. Plugging directly into a wall outlet with the original adapter can solve this.

• HDMI cable or port issues: Loose HDMI cables, damaged cables, or faulty HDMI ports can cause the Roku to restart. Checking and changing HDMI cables or ports may help.

• Weak or unstable Wi-Fi signal: Poor Wi-Fi connection can cause the Roku to reboot as it struggles to maintain connectivity. Improving Wi-Fi placement or signal strength can resolve this.

• Overheating: If the device overheats due to poor ventilation or dust buildup, it can shut down and restart to cool off. Allowing the device to cool and ensuring good airflow can stop restarts.

• Software glitches or corrupted settings: A factory reset, which erases all settings and data, can fix persistent reboot loops caused by software issues.

• Hardware faults especially in TVs with Roku built-in: Problems with backlights, main board, or power board can cause continuous restarting, needing hardware repair or replacement.

If the problem persists after trying the above solutions, contacting Roku support is recommended to diagnose potentially defective devices or complex hardware/software faults.

In summary, common causes for a Roku repeatedly restarting include power supply issues, HDMI connection problems, weak Wi-Fi, overheating, software corruption, or hardware defects. Checking each of these areas step-by-step usually resolves the issue. If not, professional support is advised.