Raspberry Pi Forums

I have 17 RPi stations set up using VGA to HDMI adapters in my classroom. I noticed three of them today had lost their video signal to the monitor, and I can not get it to come back. It works when I plug it back into a HDMI display no problem, but my monitors are all VGA and I have to use the adapters which, up until today have worked no problem. I have tried changing every setting related to HDMI in the config.txt file with no success. I did have one of the Pis start working again after booting it in to the standard HDMI connection (my classroom projector). Is there anything else that I can try without having to reload Raspbian (this fixed the same issue when I had it last year with my personal RPi). I greatly appreciate any help with this

Have you tried exchanging a working HDMI-VGA adapter with a non-functioning adapter? Where did you get the HDMI-VGA adapters from? Try swapping the power supplies while you ar at it.

MaxK1 wrote: Have you tried exchanging a working HDMI-VGA adapter with a non-functioning adapter? Where did you get the HDMI-VGA adapters from? Try swapping the power supplies while you ar at it.

+1 and are the HDMI-to-VGA adapters powered externally or just via the HDMI connection? W.r.t. to changing settings in config.txt how "systematic" were you? IE. did you use use the tvservice command to do something like this: http://www.cpmspectrepi.uk/raspberry_pi ... tings.html (easier if you can remotely login to a given pi)?
What model(s) of HDMI-to-VGA converter?
(FWIW, I've tested/used these types:
http://www.cpmspectrepi.uk/raspberry_pi ... erter.html
http://www.cpmspectrepi.uk/raspberry_pi ... rter2.html
http://www.cpmspectrepi.uk/raspberry_pi ... erter.html
http://www.cpmspectrepi.uk/raspberry_pi ... Audio.html )
Trev.

If the HDMI-VGA adapters have their own power sources, do not overlook the possibility that the PSU has "gone bad" without totally failing. A meter (and knowing how to use it!) is pretty much a "must" for anyone working with Pi's.