touch screen keeps going black!!

[martinpage23]

Afternoon, Has any one had the issue is schools where by the teachers touch screen in the class will just go black every so often. sometimes if just flashes black other times it stays black. its got to be to do with the hdmi connection but i can not see what. its happens on different makes of screen as well. i have changed the hdmi cable and updated the graphics drives but still keeps happening........ thanks in advance

[aac]

Hi there

 

Identical issues here that have been causing chaos at times. What brand and model of laptops are you using?

[LeMarchand]

Anything else connected to the screen? We had an issue where the visualisers (which, of course, were left permanently on) would occasionally try to assert dominance. Leaving them off seemed to fix the problem.

[martinpage23]

hi they range from hp to lenovo etc and some are quite new. seems to be on a benq and also a the new promethean screens . cheers

[martinpage23]

no nothing else connected. just the laptop hdmi and usb for the touch. cheers

[dhicks]

Afternoon, Has any one had the issue is schools where by the teachers touch screen in the class will just go black every so often.

 

Fiddling with the monitor refresh rate sometimes helps. I think the Windows default is 60Hz, but selecting the 59.94Hz sometimes seems to reolsve issues.

[6Foot3]

Try Win + Ctrl + Shift + B

[HC_Netman]

Couple of things that might help or at least have helped us with similar issues.

 

1. HDMI version on the display - most TVs/touchscreens have an option to change from HDMI 2 to HDMI 1.2 - this usually solves the issue.

 

2. On the device refresh rate choose an option that uses interlaced.

[aac]

In terms of trying to find a commonality do they all use the Intel ARC drivers per chance? I know Intel has been having significant issues with these...

[BenQ_Chris]

Hi @martinpage23 if you drop me DM details of the models you have I may be able to suggest some fixes.

 

You may need to switch the EDID mode on the panel from EDID 2.0 (max 4K60) to EDID 1.4 (max 4K30). There is an issue with some laptops/PCs where the GPU can do 4K60, the panels can do 4K60, but the HDMI port can only do 4K30 and causes signal drop out. The other issue can be cable length run, higher resolutions will impact the maximum cable length run (unless repeaters/extenders are used).

 

Hope to hear from you soon.

[dhicks]

You may need to switch the EDID mode on the panel

 

Good point - might be worth adding we found these EDID Emulators to help in some cases:

 

https://www.lindy.co.uk/audio-video-c2/hdmi-2-0-edid-emulator-p11244

[Clevertouch_Rob]

Apart from what @BenQ_Chris has said there are also some Generic Android Settings in EDLA screens (new style google approved panel regardless of brand) that can make this happen within the Android.

[DavR]

How many connections are your HDMI cables going through, and are you confident they're good quality cables?

 

We have our HDMI runs cabled through trunking and into a wall plate etc, which works fine most of the time, but, we have had difficulties with losing the picture in the past. Point to point with one cable was usually fine, but the cable runs + wall port connectors + fly leads caused problems. We resolved this in the end by replacing the trunked cable runs with better quality cable.

 

A good way of testing is running just a single cable, screen to PC, and see if that works better for you.

[Gusto_r53]

We have older epson EB470/570 projectors here and we get the "No Signal" screen all the time , which is probably the equivalent of what you're having. Usually its a cable run issue for us. Cables run into the trunking round to the projector, plus the wall panel, plus the extra cable to the PC. Unhappy projector due to signal loss in the lenght of the cable run.

 

I've started replacing wall panels and shorter HDMI runs from said wall panel to the projector with great success. A good quality HDMI cable also helps. Another thing which others have mentioned as well is the refresh rate + resolution. Double check all the specs for the attached devices and lower the Framerate or Resolution accordingly.