If your Sony X90J turns on then off within seconds, you're dealing with one of the most frustrating TV issues. This cycle—where the LED indicator flashes, the screen briefly lights up, then everything shuts down—usually points to power supply problems, firmware glitches, or internal hardware faults. The good news is that several fixes don't require professional repair. This guide walks you through proven troubleshooting steps to stop your Sony X90J from turning on and off repeatedly, so you can get back to watching without interruption.
Quick Fixes to Try First
Before assuming hardware failure, rule out temporary software hiccups and external device conflicts with these foundational steps.
1
Perform a Hard Power Reset: Unplug your Sony X90J from the wall outlet. Press and hold the physical power button on the TV (not the remote) for 60 seconds. Release, wait another 60 seconds, then plug back in. This drains residual power from capacitors and clears temporary memory that may cause the Sony X90J to turn on then off.
2
Test a Different Wall Outlet: Plug the TV into a known-working outlet on a different circuit. Power strips and surge protectors can degrade over time, delivering inconsistent voltage that triggers automatic shutdown. Bypass these entirely during testing.
3
Disconnect All External Devices: Remove HDMI cables, USB drives, soundbars, and gaming consoles. A faulty connected device can send an abnormal signal through HDMI-CEC, causing the TV to power cycle. Reconnect devices one by one after resolving the issue to identify any culprit.
Advanced Troubleshooting for Persistent Power Cycling
When basic resets fail, dig deeper into settings and potential hardware triggers specific to the X90J's Bravia XR processor and power management system.
4
Disable Eco Mode and Timers: If you can access menus before shutdown, navigate to Settings > System > Power & Energy. Turn off "Auto TV Standby," "Idle TV Standby," and "Sleep Timer." Also disable "Bravia Sync" (HDMI-CEC) under External Inputs, as errant signals from connected devices often make the Sony X90J turn on then off unexpectedly.
5
Check for Overheating: Inspect rear ventilation grilles for dust buildup. The X90J's full-array LED backlight generates significant heat; blocked airflow triggers thermal protection shutdown. Clean with compressed air, ensure 4+ inches clearance around all sides, and avoid enclosed cabinets. If the TV only stays on briefly after extended use, overheating is likely the cause.
6
Attempt a Forced Factory Reset: With the TV unplugged, press and hold the power button and volume down button simultaneously. While holding, plug the TV back in. Continue holding for 30 seconds until the Sony logo appears. This recovery mode can bypass corrupted firmware causing the Sony X90J to turn on then off cycle. Note: This erases all settings and apps.
Warning: If your Sony X90J emits a clicking sound, burning odor, or shows visible backlight flicker before shutting down, stop troubleshooting immediately. These symptoms indicate power board or backlight inverter failure—continuing to power cycle risks further damage or fire hazard. Unplug and seek professional service.
Still Need Help With Your Sony Device?
If these steps didn't resolve the turns on then off issue, our certified technicians can help.
Why does my Sony X90J keep turning on and off by itself?
Automatic power cycling typically stems from HDMI-CEC conflicts (Bravia Sync), corrupted firmware, failing power supply capacitors, or overheating protection activation. Start by disconnecting all devices and performing a hard reset to isolate the cause.
Can a software update fix my Sony X90J turning on then off?
Yes, if you can keep the TV running long enough to update. Check Settings > System > About > System Software Update. However, if the shutdown happens too quickly, you'll need to use Sony's USB firmware recovery method or request service.
How much does it cost to repair a Sony X90J that won't stay on?
Power supply repairs typically range $150-$300, while main board replacement runs $200-$400. Backlight repairs vary widely. Given the X90J's value, compare repair estimates against replacement costs—professional diagnosis helps determine the most economical path.