M: [Non-text content: image_asset_pointer; content_type=image_asset_pointer; size_bytes=362803]
This is the panel on the back of my older television. I need you to go online and using the information there, figure out the best resolution I would be able to get if I hooked this up to a computer and how to get it to there. To give you context, there's another TV I was using, and after screwing around with settings a couple of years after I started using it, I found out there was a particular setting that suddenly gave it a full and pure native resolution that was much clearer than the version I had been using before. Now, that TV is currently being used elsewhere, but I'd like to get the best resolution and crispness as I can out of this one. This is for a computer running Ubuntu Linux, so I don't know if that matters in terms of the resolution that's possible. I don't want simply the highest resolution. I want the one that's going to give me the clearest and most usable picture. I'm like, I don't want something that's a little bit higher, but also using some sort of driver tricks or anything like that to make it act as though it has a higher resolution than it actually can display. That's what was going on with the last TV, and I'd rather avoid that.
G: TL;DR:
That model is a native 1080p panel (1920×1080 @ 60Hz).
The “crisp” mode you’re remembering is almost certainly 1:1
pixel mapping (“Just Scan” / “Full” / no overscan) via HDMI.
Use HDMI, set 1920×1080@60, and disable overscan on both the TV and
Ubuntu.
From the label: Panasonic TC-L42U5 (2012)
That series is a Full HD (1920×1080) LCD, not 720p.
You’re thinking about this correctly—native resolution + proper mapping beats “higher” fake modes.
Best/cleanest output:
Anything like:
On Panasonic TVs, this is usually:
If not labeled that:
Without this, the TV slightly zooms the image → blur + cut edges (what you probably had before).
HDMI gives:
Quick GUI path:
xrandr (optional but precise)Run:
xrandrLook for your HDMI output (e.g., HDMI-1) and
confirm:
1920x1080 60.00*If it’s not selected:
xrandr --output HDMI-1 --mode 1920x1080 --rate 60On AMD/Intel (most likely for you): usually fine automatically.
If you see:
Fix:
Some Panasonic sets only enable “Just Scan” when the input is labeled as PC.
If you don’t see the option:
There’s no hidden higher mode here—you’re not unlocking something
beyond 1080p.
The “aha” moment is removing scaling, not increasing
resolution.
If you want, tell me what GPU you’re running and I’ll sanity-check whether Ubuntu might be doing anything weird on your specific setup.
M: It's working fine. Appreciate the help. Now I need to know if I can turn off or at least increase the auto-off timer for the TV because it keeps switching off well before the computer does if I leave it for an hour or two. Honestly, I'd rather just be able to turn it off and on manually. None of this timer crap, but if it's an impossibility to turn it off, the second best choice would be just to extend that timer.
G: TL;DR:
Yes, you can stop that. On that Panasonic, it’s usually “Auto
Power Off” / “No Signal Power Off” / “Sleep Timer.” Turn them
Off, or set them to the longest time. Also disable
HDMI control (VIERA Link) so the TV doesn’t decide to
shut down on its own.
Panasonic stacked a few different “helpful” shutdown features:
No Signal Auto Off
→ TV turns off after ~10–15 min if it thinks nothing is
happening
Sleep Timer
→ Manual timer (30/60/90/etc)
Auto Power Off (Inactivity)
→ Turns off after X hours regardless of signal
VIERA Link (HDMI-CEC)
→ Can power off the TV based on device behavior
Go through this path:
This prevents weird “I think the device is idle, I’ll shut down” behavior.
Even if your PC is “on,” it may:
The TV sees that as “no signal” → powers off
Then your PC is the culprit, not the TV:
Check Ubuntu:
Or extend them past your TV timeout.
You can absolutely disable this behavior entirely.
Panasonic just buried it under “Eco” like it’s doing you a favor.
Once:
…it should behave like a normal, obedient display instead of a passive-aggressive one.