[SOLVED] Resolution not scaling correctly to TV

whatsforbreakfast · Post by **whatsforbreakfast** » Sat Aug 01, 2020 2:04 am

Hey guys, I recently picked up an old Dell Optiplex 990 with an old Radeon 5000 series card to setup in the living room as a media centre PC running Linux Mint. The problem I'm having is getting the resolution to scale correctly to the TV, where right now the best I can do results in black bars on the sides. The Dell came with Windows 10 installed which output 1920x1080 to the TV without any problems, but I wiped that and put Mint on and Mint only gave me resolution options for 640x480 and 1024x768.

1024x768 fit the TV just fine with very thin unnoticeable black bars, but obviously trying to watch 1080p content at this resolution doesn't really work

So I did some digging and found this thread here

viewtopic.php?t=219820

and after following the instructions from user roblm I have made some progress. I can now get the computer to output 1920x1080 to the TV, however I'm experiencing big black bands that are very noticeable and were not present on Windows 10, or from my Mint laptop. Here's what I did:

Created an xorg.conf file and added the following

Code: Select all

Section "ServerLayout"         
   Identifier   "Layout0"		 
   Screen   0 "Screen0" 0 0  
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    HorizSync       24.0 - 94.0	  
    VertRefresh     24.0 - 85.0
    Modeline "1920x1080R"  138.50  1920 1968 2000 2080  1080 1083 1088 1111 +hsync -vsync
EndSection   

Section "Device"
    Identifier     "Device0"
    Driver         "radeon"
    Option "UseEDIDFreqs" "false" 	
    Option "UseEdidDpi" "false"
EndSection

Section "Screen"				
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    Option "DPI" "96x95" 
    DefaultDepth    24
    Option "Metamodes" "1920x1080_60 +0+0"  	 
    Option "ModeValidation" "AllowNonEdidModes"   
EndSection

This resulted in the following

I then tried the alternate modeline code recommended by roblm

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Modeline "1920x1080R"  138.50  1920 1968 2000 2080  1080 1083 1088 1111 +hsync -vsync

This turned out a lot better, but still not quite all the way there

The TV is already configured to work with computer resolutions, as Windows 10 looked fine, and also my Mint laptop when I hook that up looks just fine too and fills the screen nicely. I'm wondering, is there some change to those modeline numbers I can make to get it to fit right? Or alternatively, is there some config file on my laptop I can copy that will output the correct resolution for this particular TV? I checked but there's no xorg.conf and I don't know if there's something else like it. The laptop outputs over HDMI, and the Dell is converting from DVI which is probably why it can't identify the TV and output correctly in the first place.

Would really love a hand on this one if anyone knows

~ EDIT ~

I did it!

So after some Google-fu I found this great webpage here https://arachnoid.com/modelines/
It goes into detail on fine tuning the values of the modeline and what I needed to adjust was the HSyncStart, HSyncEnd, and HTotal values. Here's what I ended up with for my particular TV

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Modeline "1920x1080R"  138.50  1920 1952 1984 2048  1080 1083 1088 1111 +hsync -vsync

Hope that proves useful for anyone else down the line