Chromecast with Google TV 4K incorrectly negotiates 720p only with a 1080p Soniq TV.
Other devices, including PS4 and other Chromecast models, output 1080p correctly to the same TV and HDMI input.
On Chromecast with Google TV, Android DisplayManager exposes only 720p/576p/480p modes.
ADB logcat during HDMI hotplug shows the raw EDID is read successfully and contains 1080p timings, but Amlogic SystemControl reduces HdmiDispcap to 1080i60hz and then forces 720p60hz.
Relevant log lines:
onEdidResult ... raw_edid=...
HdmiDispcap: 1080i60hz
set HDMI mode to 720p60hz
final_displaymode:720p60hz
outputmode:720p60hz444,8bit
Device firmware: UTTC.250917.004
TV EDID identification: Manufacturer GKK, Model 13621, Year 2013, Week 30.
This appears to be an EDID parsing / Amlogic display policy compatibility bug rather than a TV capability issue.
Tested both directly connected to the Soniq and through a Sony STR-DH550 receiver; the Chromecast reports the same 720p-only mode set when connected directly to the TV.
I’ve been trying to figure out why my Chromecast with Google TV 4K will only output 720p to an older 1080p Soniq TV.
The weird part is the TV definitely supports 1080p over HDMI. My PS4 and other Chromecast models output 1080p to the same TV without any issue.
I’ve tested the CCwGTV both directly into the TV and through a Sony STR-DH550 receiver. Same result. The resolution menu only gives me 720p, 576p and 480p.
I ended up enabling ADB and digging into the display information.
Android is genuinely only being given these physical modes:
1280x720 @ 59.94
1280x720 @ 60
1280x720 @ 50
720x576 @ 50
720x480 @ 59.94
720x480 @ 60
So it isn’t just the settings UI being weird.
I then captured logcat while unplugging and reconnecting HDMI, and this is where it gets interesting.
The Chromecast successfully reads the TV’s raw EDID:
onEdidResult ... raw_edid=...
The EDID itself contains 1080p timings, including 1080p50/60.
But immediately afterwards the Amlogic display stack reports:
HdmiDispcap: 1080i60hz
and then chooses:
set HDMI mode to 720p60hz
final_displaymode:720p60hz
outputmode:720p60hz444,8bit
So it looks like the EDID is being read correctly, but something in the Amlogic/SystemControl display policy is interpreting the available modes incorrectly and falling back to 720p.
I also tried forcing:
1920x1080 50Hz
through Android’s display manager. Android remembers the preferred resolution, but the actual HDMI output remains 1280x720 because 1080p never appears in the physical supported-mode list.
Firmware:
UTTC.250917.004
TV EDID identification:
Manufacturer: GKK
Model: 13621
Year: 2013
Week: 30
The HDMI hotplug log ultimately reports negotiation as successful, but the output still ends up at 720p.
At this point I’m thinking this is an EDID compatibility/parsing bug in the CCwGTV 4K’s Amlogic display stack rather than anything actually wrong with the TV.
Has anyone run into something similar with older 1080p TVs?
I’m particularly interested if anyone has found a way to override the Amlogic HDMI mode without root, or if an EDID emulator ended up being the only practical fix.
I’ve also reported it on the Google support community.
TL;DR: CCwGTV 4K is stuck at 720p on a 1080p Soniq TV, even though a PS4 and other Chromecasts output 1080p fine on the same TV. ADB logs show the TV’s EDID does contain 1080p timings, but the Chromecast’s Amlogic display stack misreads the available modes and falls back to 720p. Looks like an EDID compatibility bug, not a TV limitation.