Hi @Gogu_,

Thank you for reporting your issue to our community.

If your Range Extender can't be powered on properly, not responding to reset or repeat to reboot itself, please refer to the following suggestions:
1. Please plug the extender into another power socket.
2. Hold the reset pinhole until all the lights turn on for one second, then off.
Note: If the reported models are RE220 V3/RE200 V5/RE190 V5, always repeat to reboot, after trying the above troubleshooting methods, please refer to https://community.tp-link.com/en/home/forum/topic/653040 for further suggestions.
If it is still the same, please contact local technical support for further help, which may help you check the warranty.