pkilcoyne
Posts: 6
Joined: Sat Apr 05, 2014 10:09 pm

Black border on screen of HDMI2

Thu Nov 07, 2019 5:17 pm

Hi all,
I recently bought the new Raspberry pi 4 and have connected it up to two 40" screens.

Odd thing is the screen connected to HDMI2 has a black border around it.

Is there any way of removing this?

Thanks,

P

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MikeDB
Posts: 167
Joined: Sun Oct 12, 2014 8:27 am

Re: Black border on screen of HDMI2

Thu Nov 14, 2019 8:46 pm

I have the same on both screens. There are some lines in the config.txt which are supposed to fix the problem but as all too often is the case these things don't seem to have been tested.
Will the forthcoming MIDI-2 spec at last allow us to set the volume to 11 !!

6by9
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: Black border on screen of HDMI2

Thu Nov 14, 2019 10:32 pm

MikeDB wrote:
Thu Nov 14, 2019 8:46 pm
I have the same on both screens. There are some lines in the config.txt which are supposed to fix the problem but as all too often is the case these things don't seem to have been tested.
So what are these random lines that you have tried and we haven't tested? Crystal balls are in short supply.

IIRC disable_overscan=1 should do it, but it may have become a bitmask and need to be disable_overscan=3 (ie 1=disable on HDMI0, 2=disable on HDMI1, 3=disable on both)
Edit: disable_overscan=1 is all that is required.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

RossDv8
Posts: 244
Joined: Thu Jan 21, 2016 12:35 pm

Re: Black border on screen of HDMI2

Thu Nov 14, 2019 11:17 pm

I had a black border around one of my screens and messed with config.txt and a heap of other stuff with no result.
Then I found an obscure setting to change the aspect ratio on the HDMI TV.
Your post says 'screen'. It does not say whether you are using a TV as a display or a dedicated HDMI monitor. One of the reasons people with a technical background get frustrated with questions, is that they don't have crystal balls.
Anyway, I found my answer in a setting in the TV Menu that changes the Aspect Ratio of the picture. It had all the standard ones, and the default was something like 16:9.
I accidentally tried 'Just scan' because I was curious. And the black lies were gone when I went back to the Pi 4. It was strange, because the Pi 3B+ worked ok on the TV's default setting.

I checked my HDMI computer monitor, and it has a button on the side to change aspect ratios, and cycling that does the same thing. A couple of those settings get rid of the black border.

This might not fix your problem, but it might give you some ideas to look at...
Remember, nobody is listening to you
until you fart ...

pkilcoyne
Posts: 6
Joined: Sat Apr 05, 2014 10:09 pm

Re: Black border on screen of HDMI2

Sun Nov 24, 2019 6:10 pm

Hi all,
setting disable_overscan=3 in config.txt did the trick.

Thanks,

PK

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MikeDB
Posts: 167
Joined: Sun Oct 12, 2014 8:27 am

Re: Black border on screen of HDMI2

Sun Nov 24, 2019 11:25 pm

6by9 wrote:
Thu Nov 14, 2019 10:32 pm
MikeDB wrote:
Thu Nov 14, 2019 8:46 pm
I have the same on both screens. There are some lines in the config.txt which are supposed to fix the problem but as all too often is the case these things don't seem to have been tested.
So what are these random lines that you have tried and we haven't tested? Crystal balls are in short supply.

disable_overscan=1

followed by
overscan_left (and _right, _top and _bottom) = -16

Definitely failed with a pair of Samsung 32" 4k monitors on whatever version of Buster on Pi 4 I was using last month but is now working with the latest update.

But the occasional flashing on and off of the monitors is still there in full 4k mode. Switching to a lower resolution fixes the problem. Gentoo has the same problem so possibly something hardware related ?
Will the forthcoming MIDI-2 spec at last allow us to set the volume to 11 !!

6by9
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Raspberry Pi Engineer & Forum Moderator
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Location: ZZ9 Plural Z Alpha, aka just outside Cambridge.

Re: Black border on screen of HDMI2

Mon Nov 25, 2019 7:34 am

MikeDB wrote:
Sun Nov 24, 2019 11:25 pm
disable_overscan=1

followed by
overscan_left (and _right, _top and _bottom) = -16

Definitely failed with a pair of Samsung 32" 4k monitors on whatever version of Buster on Pi 4 I was using last month but is now working with the latest update.

But the occasional flashing on and off of the monitors is still there in full 4k mode. Switching to a lower resolution fixes the problem. Gentoo has the same problem so possibly something hardware related ?
Overscan was only added as an option on the pi4 with FKMS relatively recently.
Disable_overscan=1 makes all other overscan_ tags redundant as it is disabled.

4k display being intermittent like that sounds like a dodgy cable. 4k does weed out lower quality cables as it is a faster link speed than lower resolutions.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

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MikeDB
Posts: 167
Joined: Sun Oct 12, 2014 8:27 am

Re: Black border on screen of HDMI2

Mon Nov 25, 2019 11:52 am

6by9 wrote:
Mon Nov 25, 2019 7:34 am
MikeDB wrote:
Sun Nov 24, 2019 11:25 pm
disable_overscan=1

followed by
overscan_left (and _right, _top and _bottom) = -16

Definitely failed with a pair of Samsung 32" 4k monitors on whatever version of Buster on Pi 4 I was using last month but is now working with the latest update.

But the occasional flashing on and off of the monitors is still there in full 4k mode. Switching to a lower resolution fixes the problem. Gentoo has the same problem so possibly something hardware related ?
Overscan was only added as an option on the pi4 with FKMS relatively recently.
Disable_overscan=1 makes all other overscan_ tags redundant as it is disabled.

4k display being intermittent like that sounds like a dodgy cable. 4k does weed out lower quality cables as it is a faster link speed than lower resolutions.
Yes that was my first thought but they are the Samsung ones and I've tried others just to confirm. Just to clarify, the flashing is only in 64 bit mode, which I didn't make clear.

In another thread - Pi4 64-bit raspbian kernel for testing - Focus on Pi4 - refering to Gentoo, Sakaki replied as follows
sakaki wrote:
Wed Oct 16, 2019 11:30 am
If your monitor currently works in Raspbian, then it is likely to be a combination of the kernel + RPi boot firmware versions causing the flashing issues you experienced. Both have been going through a rapid evolution since the RPi4 was launched.

hth, sakaki
I never got rid of the problem with Gentoo either. But with the standard 32 bit kernel, everything has always been fine.
Will the forthcoming MIDI-2 spec at last allow us to set the volume to 11 !!

RossDv8
Posts: 244
Joined: Thu Jan 21, 2016 12:35 pm

Re: Black border on screen of HDMI2

Tue Nov 26, 2019 1:47 am

If you recently changed from 32 bit to 64 bit, but are plugged into the same monitor or TV, especially if it is UHD, consider checking your TV menu for something like 'Aspect Ration' under the Picture part of the Menu.

My UHD TV came with a default setting, I think it was something like 19:10. I tried a few settings and one that said 'Just Scan' got rid of the problem with either a black border, or the panel being OFF the screen. None of my messing with config.txt in the week or so before I thought to look there helped at all.

If it is a monitor rather than a TV, there might be a button on the side for scanning the connected device refresh.
Since setting the TV to Just Scan, I have tried a fresh install of Buster, and an install of Manjaro on microSD, and both worked with no mods to anything.

This setting in the TV/Monitor might not fix your problem, but it was the only simple solution for me.. It could be worth checking if you haven't already.
Remember, nobody is listening to you
until you fart ...

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MikeDB
Posts: 167
Joined: Sun Oct 12, 2014 8:27 am

Re: Black border on screen of HDMI2

Tue Nov 26, 2019 12:02 pm

RossDv8 wrote:
Tue Nov 26, 2019 1:47 am
If you recently changed from 32 bit to 64 bit, but are plugged into the same monitor or TV, especially if it is UHD, consider checking your TV menu for something like 'Aspect Ration' under the Picture part of the Menu.

My UHD TV came with a default setting, I think it was something like 19:10. I tried a few settings and one that said 'Just Scan' got rid of the problem with either a black border, or the panel being OFF the screen. None of my messing with config.txt in the week or so before I thought to look there helped at all.

If it is a monitor rather than a TV, there might be a button on the side for scanning the connected device refresh.
Since setting the TV to Just Scan, I have tried a fresh install of Buster, and an install of Manjaro on microSD, and both worked with no mods to anything.

This setting in the TV/Monitor might not fix your problem, but it was the only simple solution for me.. It could be worth checking if you haven't already.
Oddly enough I had to do this yesterday for a new 43" TV monitor for my PC setup, but the Pi has two standard Samsung 32" 4k monitors which I've just had a good check of and there doesn't seem to be any buttons at all. One thing I notice is that the Pi4 64 bit boot time is noticeably faster than 32bit so I wonder if some critical step is being skipped over. It's not a killer anyway - the eventual application will be headless once I get one of the Pi4s to reliably connect directly to an Android tablet via it's own WiFi, not via the local router.
Will the forthcoming MIDI-2 spec at last allow us to set the volume to 11 !!

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