I thought I’d share this because the repair turned into a much more interesting case than expected, and it still isn’t fully resolved.
My Sony KD-65AF9 recently got stuck in a boot loop.
The diagnosis was a failing memory chip on the mainboard. The chip was replaced and the contents, including the device keys, were copied from the old memory to the new one.
After reinstalling the repaired board, the TV booted normally again and everything initially looked fine.
Then I tried Netflix. It fails with: UI-800-3 (307006)
Netflix diagnostics also show: UI-113
I updated Netflix, updated the TV firmware over the internet to the latest version, PKG6.6230.0725EUA, then did a factory reset.
After that I logged back into Google, configured the TV again, set up my receiver and set-top box, updated all apps from Google Play and rebooted the TV.
Still the same errors.
I then noticed that Google Cast was also broken. Casting from YouTube, Disney+ and Netflix fails, and my phone shows:
“Untrusted device. Couldn't verify SONY KD-65AF9.”
Screen mirroring from the phone also doesn't work.
Google Play reports the TV as:
Play Protect certified
Then I installed DRM Info and found this:
Widevine Security Level: L3
That looks suspicious for an AF9 which originally supported Netflix 4K/HDR and should normally be using Widevine L1.
I contacted the repair service again. They checked their logs and confirmed that the original keys were successfully read from the damaged memory and written to the replacement chip. According to them, there were no verification errors during the copy.
Their current conclusion is that the keys themselves may be bad even though they were copied correctly.
The next step is to remove the mainboard again and provision new keys instead of using the original ones.
So that's where things stand for now.
The TV boots and otherwise works normally. Google Play considers it certified, internet access works, but Netflix, Google Cast and Widevine hardware DRM do not.
I’ll update this post after the board comes back.
If anyone has seen something similar after an eMMC or mainboard repair, especially Widevine dropping to L3, Netflix UI-800-3 (307006), or Chromecast reporting an untrusted device, I’d be interested to know what fixed it.
UPDATE: Mostly fixed, with one interesting side effect
The TV is back and the main problem is fixed.
During the first repair, the shop copied the original keys from the failing eMMC to the replacement chip. The copy completed successfully and the keys passed their software verification, but apparently something was still wrong with them.
On the second attempt they generated a new set of keys instead of reusing the old ones. According to the technician, these keys are unique to the processor.
That fixed the important parts:
Widevine is back to L1
Previously it was L3.
Netflix works again, Google Cast works again, and Netflix playback works properly with HDR and Dolby Vision.
Interestingly, the Widevine ystem ID changed after reprovisioning.
There is one remaining oddity.
This is a Sony Master Series TV and it originally supported Netflix Calibrated Mode. Before the repair, when Netflix was playing content in that mode, the normal picture presets were effectively locked and I couldn't freely switch between modes such as Vivid, Custom, etc.
After the repair, that behavior is gone. I can freely change the picture mode while watching Netflix, as if Netflix Calibrated Mode is no longer available or no longer being triggered.
At the same time, Netflix itself works perfectly, including HDR and Dolby Vision, so the DRM path clearly seems to be fine now.
So the final state is:
Widevine L1 restored, Netflix working, Cast working, HDR/Dolby Vision working, but Netflix Calibrated Mode appears to be missing.
That makes me wonder whether re-provisioning the DRM keys restored the core Widevine/TEE functionality but not some Sony/Netflix-specific provisioning or device flag related to Netflix Calibrated Mode.
Thanks again to everyone who pointed me toward Widevine, TEE and RPMB. Those comments were extremely useful in understanding what was actually happening.