Hi All!
I got a very strange hardware issue and a few days of testing is making me suspect my Gambas app is somehow the problem.
The set up is with a Dell touchscreen monitor connected to a pc running Debian 12 acting as an appliance and running my Gambas app full screen.
The issue is the Dell monitor has suddendly but consistantly been losing the signal from the vga connection and the screen goes blank and touching the screen or keyboard does not bring it back. I have screensaver off as well as preventing screen blanking because like I said, it's being used like an appliance.
I won't bother listing all the troubleshooting I've done but I'll say I have ruled out problems with that Dell monitor and mulitple pcs I've tested on.
I can only reproduce what's happening when my Gambas app is running.
This just suddenly started happening last week. Nothing has changed on the pc running the app other than Debian updates.
Is it somehow possible my Gambas  app is causing this?
This is so weird.

You say, "I can only reproduce what's happening when my Gambas app is running". It makes me wonder if the problem is in your code. Can you step through the program to find out which line causes the problem, or post the code so that we can try it on different Distros to see what happens?

 I would ask if all the computers you tried are using the same version of Debian and the same version Gambas.  Debian is notorious for breaking things in update and taking forever to repair. It is why I stopped using it. Are the other computers the same in hardware? and do they exhibit the same problem? If the computers have the same hardware and same versions of software you may be seeing an obsoleted video driver problem. Assuming it is not in the coding. Video modes might be the trigger. Try running your program not in full screen to test.

 Thanks for the input guys. I'm still testing with different computers and with non-touch monitors. This app ran great for months and months with no problems at all. The only reason I'm looking at the app is that the screen blanks (monitor says no vga signal) is when the app is running. I've let the pc run all day without my gambas app running and no screen blanks at all.  I know it's unlikely that gambas is the cause….this is just weird. To make it even more mysterious, the app ran all day yesterday with NO screen blanks at all…..also no screen blanks so far today as of this post. I'll keep testing and report back later.

BTW, I do kind of wonder if the monitor is the cause. Maybe it is nearing the end of its life. I don't remember exactly when I got it but it is close to 8 years old at least. I hope not though…that wasn't a cheap monitor and I do love it!

 Quick update: i just tapped one of the buttons on the app and the screen blanked immediately. Hitting a key on the keyboard is not bringing the monitor back up. Monitor flashed "no vga signal". Maybe a Debian update broke something in the touch process or even power management or maybe this monitor is nearing the end of its life. So weird.

FYI: screen saver is off as well as power management blanking the screen after a set time.

 I'm still troubleshooting this for anyone interested. I am still not convince the monitor is dying. I really think this is a software issue but not necessarily Gambas causing it. I suspect a Debian 12 update broke something. I have no idea what though. I've been very happy with Debian over the years and have never seen/noticed an update break something so this is surprising….at least to me. I'm prepping the same pc with a hard drive that has Ubuntu 22 on it. I just need to get some stuff installed and then my gambas app and then see what happens.

 I have been working on this as well as my X11 issue. I tried a 3rd pc, a Dell core duo similar to the other 2 Dells but slightly newer. Just swapped the hard drive with one of the others so still Debian 12. Running for a couple days now with no screen blanking. So I guess both the other older Dell machines both have vga issues but I'm only 75% sure of this. Weird because what's the chances both those older Dells have the same vga issue and only seem to blank the screen when I tapped a button on my Gambas app.

 because what's the chances both those older Dells have the same vga issue and only seem to blank the screen when I tapped a button on my Gambas app.


They probably have different video chips or different video cards and the latest update does not work properly with the older hardware.

 Yep, that what i was thinking as well. All 3 Dells are different models of the Optiplex line. I guess pc #3 doesn't have that problem.

 check the specks for the three machines and see what video they use.

then you might file a report with Debian

grayghost4 said

check the specks for the three machines and see what video they use.

then you might file a report with Debian

Thanks, I'll do that when I get a chance.