Tombee3D
Posts: 2
Joined: Thu Mar 14, 2019 5:21 pm

Display problems: Monitor v. TV

Thu Mar 14, 2019 5:59 pm

Hi,

I've just joined this forum so I can find a resolution to an issue I have. I am an absolute newcomer to RPi stuff, and Linux, so please bear with me. (I have already searched though the forum, but to no avail, unless I missed something on the way).

Last year I purchased a Rasp Pi 3 B+, purely for use on my model railway using JMRI and DCC and its facility to control the railway using a mobile phone/tablet via wifi.

When I received it, all was working fine. I could connect it to my computer's (Desktop WIN10...I know!) Acer S220HQL monitor using a HDMI cable through a DVI-D adaptor. That was not a problem. I could do what I wanted. I could also connect to my TV through HDMI cablw connection.

However, about a month ago, I was no longer able to use the monitor. All I get is a blank screen when powering on the Pi, after an initial "no signal detected". BUT connecting to the TV is not affected.

I have tried using HDMI /DVI-D cable (no adaptor) on monitor. ( I have purchased and used 3 different such cables from 3 different manufacturers to no avail).

Some useful advise would be greatly appreciated. i do not like the thought of transporting a 48" TV top model railway exhibitions. A small monitor would be more practical.

Many thansk
Tom

bertlea
Posts: 265
Joined: Wed Dec 07, 2016 6:33 am
Location: Hong Kong

Re: Display problems: Monitor v. TV

Fri Mar 15, 2019 4:02 am

It sounds like your monitor is no longer working, nothing to do with the Pi (as it works when connected to a TV). Are you saying the monitor is still working if connected to other computer such as a PC?

W. H. Heydt
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Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Display problems: Monitor v. TV

Fri Mar 15, 2019 4:23 am

Welcome to the forums.

If, as mentioned above, your monitor works correctly with other devices, such as your PC, I suggest you be sure to seat the cables fully, make sure the monitor is turned on, and then connect the power to the Pi. One other thing that might help, which can be done directly to the SD card, or through an SSH session, is to set the force_hdmi flag so that the Pi won't decide it doesn't "see" an HDMI device and switch to composite video output.

Tombee3D
Posts: 2
Joined: Thu Mar 14, 2019 5:21 pm

Re: Display problems: Monitor v. TV

Sun Mar 17, 2019 11:00 am

Thank you for replies.

The monitor DOES work when connected to PC. In fact, I'm using it now to type this post.

I have already set the force_hdmi flag accordingly since the monitor stopped working with the Pi, to no avail.

All cables are correctly set. As a retired computer (hardware) engineer, I do have a little knowledge in that field.

One final thing that I have noticed is that, when, having connected the monitor to the Pi and having powered the monitor on, upon powering the Pi and after a few seconds of the "no signal detected" the monitor just switches off as indicated by the monitor power LED although the Pi is still powered.

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FTrevorGowen
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Re: Display problems: Monitor v. TV

Sun Mar 17, 2019 12:55 pm

Tombee3D wrote:
Sun Mar 17, 2019 11:00 am
Thank you for replies.

The monitor DOES work when connected to PC. In fact, I'm using it now to type this post.

I have already set the force_hdmi flag accordingly since the monitor stopped working with the Pi, to no avail.

All cables are correctly set. As a retired computer (hardware) engineer, I do have a little knowledge in that field.

One final thing that I have noticed is that, when, having connected the monitor to the Pi and having powered the monitor on, upon powering the Pi and after a few seconds of the "no signal detected" the monitor just switches off as indicated by the monitor power LED although the Pi is still powered.
Can you remotely log in to said pi in those circumstances and run the tvservice -s** command? That should tell us what the pi thinks it's connected to.
Trev.
** FWIW, more info here: http://www.cpmspectrepi.uk/raspberry_pi ... tings.html
Still running Raspbian Jessie on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W) but Stretch on my 2xP3A+, P3B+, P3B, B+, A+ and a B2. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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