: Historically, updates for this series added support for high-quality 4K HDMI (4:4:4 60Hz) signals and new system settings for RS232 control. : Addresses specific hardware handshakes, such as connectivity or sound synchronization issues.
| Symptom | Most Likely Cause | Solution | | :--- | :--- | :--- | | | Corrupt cache partition after update | Perform a forced factory reset: With TV off, press and hold Volume Down + Power on the TV body for 15 seconds. | | No sound from HDMI ARC | CEC/ARC data structure changed | Go to Settings → External inputs → BRAVIA Sync settings → Toggle BRAVIA Sync off/on . Then power cycle your soundbar. | | Wi-Fi says "Disabled" | Firmware reset the MAC filter table | Go to Network & Internet → Wi-Fi → Forget network → Reboot router → Reconnect. | | Apps won't open (Netflix error NW-3-6) | DRM libraries updated but app data outdated | Uninstall the app → Reinstall from Play Store. Do not restore from backup. | | Remote feels sluggish | IR profile changed | Replace batteries (firmware changes polling rate, affecting old batteries). Then re-pair Bluetooth remote: Settings → Remotes & Accessories → Add accessory → Press Volume Down + Home for 5 secs. | Firmware Change Update on SONY KD-43X8309C
This article details the .
Fixed sound-skipping issues with external soundbars like Sonos and improved HDMI ARC reliability. How to Change or Update Your Firmware Method 1: Automatic Update (Recommended) : Historically, updates for this series added support
This is the easiest method and ensures you receive notifications as soon as new software is available. Drivers and Software updates for KD-43X8309C - Sony UK | | No sound from HDMI ARC |
Previous major updates transitioned the system from Android Lollipop to Marshmallow and eventually Nougat , introducing Task-switching and Picture-in-Picture modes.
A long-standing stable release widely used for this model.