A few days ago CEC (Bravia Sync if you prefer Sony's branding) stopped working on my PlayStation 3, the device wouldn't even show up as a player in the device list on my TV (Sony BRAVIA 46W905A).  After much head scratching and attempts to fix it via the TV settings and plugging/unplugging of cables I finally found a way to get it operational again by resetting the PS3's display settings.

Sony BRAVIA 46W905A

  1. Disable BRAVIA Sync on the TV (Home > Settings > External Inputs > BRAVIA Sync Settings).
  2. Power off the PS3.
  3. Power on the PS3.  Continue to hold the power button down for approximately 5 seconds until you hear a second beep.  This resets the display settings, when your PS3 comes back online you'll be prompted to enable HDMI display and confirm you can view the message on screen.
  4. Enable BRAVIA Sync on the TV again.

I didn't even need to run the search for new devices, as soon as I re-enabled BRAVIA Sync the PS3 showed up in the device list again and CEC was working as normal once again.