This question is not specifically a Pi question, but about how to FORCE the Pi
hdmi to wake my monitor from sleep, which seems to be a seems to be specific to the Pi hardware, although it may be a foible of the monitor.
I have a monitor (Samsung SyncMaster 740B) connected to my Pi. (The monitor is connected via a DVI-hdmi converter and a 3 port hdmi switch, but even direct connection often fails.) Normally this works well, however I seem to have problems waking it up.
I normally turn the monitor off when not in use for a period, but on power up the display remains blanked. The LED in the power button blinks, normally solid when running. If I leave it in this state (turned on, blank display) it eventually springs to life, but this takes quite some time. Once it has woken up everything works as normal.
I have tried many ploys to wake it up.
Pressing Shift key usually wakes other computers, but has no effect on the Pi.
tvservice -o in various combinations seems to have little effect.
The Pi responds to keyboard (I can log on and see a new session over
ssh on another computer), can restart, switch
tty, but the display remains stubbornly blank.
I have tried
tvservice -c "PAL 4:3" followed by
I have also tried switching virtual consoles, unsuccessfully.
Even restarting the Pi does not always work.
Does anyone have any suggestions.