Raspberry Pi Forums

Hello,

i'm currently in Nepal setting up an IT Lab for education. It was not easy to get DVI monitors. But finally there are brand new ViewSonic VA2046m LED monitors. The monitors are connected via the DVI cable and a DVI/HDMI Adapter (http://www.amazon.de/Wentronic-Adapter- ... +Buchse%29) .

If I'm using the a SD Card with a new copy of NOOBSv1_1 I and I start the Raspberry the monitor says no signal. If I'm unplugging the cable from the raspberry ... wait a little bit I will get the installation page on the screen. After installing, the raspberry needs to reboot. The red light PWR is glowing, but again there is no signal at the monitor. After unplugging the cable again, the green light (OK) starts to glow. The Raspberry seems to boot, but I won't get a signal after plugging in again. After uncommenting hdmi_force_hotplug=1 in /boot/config.txt unplug the cable .. wail until the OK light is glowing und plugging it in again. I will get the signal again.

So at the moment for every booting phase it is necessary to unplug ... wait ... plug the monitor in again to get the screen running.

I tried also some modifications from http://elinux.org/RPiconfig to avoid unplug / pugging it in again.
Some of them I tried alone ... some of them I tried in combination:
hdmi_safe=1

config_hdmi_boost=4
hdmi_drive=1
hdmi_ignore_cec=1
avoid_edid_fuzzy_match=1
hdmi_ignore_edid=0xa5000080

/opt/vc/bin/tvservice -m CEA
Group CEA has 0 modes:

/opt/vc/bin/tvservice -m DMT
(prefer) mode 83

There is a better resolution by using:
hdmi_mode=83
hdmi_group=2

Does anybody know how to solve this problem? Thanks so far.
Greetings from Sauraha, Nepal
Jojen

hdmi_force_hotplug=1 is probably all you need
can you try latest raspbian and not latest noobs

if you are using noobs then with a fresh install hitting keys 1,2,3,4 should get you a displayable screen initially [after it has booted things change I think]

in my setup unfortunately i won't get a picture on the screen with a fresh installation from NOOBS after pressing 1234. I have to unplug ... wait and plugging it in again, to get the picture.
Currently I'm downloading the new version of raspbian. But it can take some time, because slow internet connection and power interrupts ;/

Thank for your support. In the latest Version of Raspbian it works!

Unfortunately i have to refresh this thread again. In the Lab there are 8 Raspberry Pis. All of them are based on the same Image in Version 2013-07-26-wheezy-raspbian and are copys. If I turn on power supply some of them starts directly booting. But others needs more time to boot. Some of them needs so much time you won't wait. If you take one of them, unplug the monitor ... wait a little bit and pug it in again, the raspberry starts booting.
We had a problem of earthing in the power supply in the past but our electrician told us, this should be fixed right now.
Is there someone who has any additional ideas? Thanks for your help!