I tried to change different lines in the /boot/config.txt and rebooted after each try without any success, once I don't remember which settings I had, I got a signal, but it was just for a one second followed by several seconds black screen and these two states were repeating, but of course not usable.

$ tvservice -s
 
state 0x12000a [HDMI CEA (16) RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive

I tried to change different lines in the /boot/config.txt and rebooted after each try without any success.

This is what I've tested:

• hdmi_force_hotplug=1
• hdmi_group=2 & hdmi_mode=46/hdmi_mode=47
• hdmi_drive=2
• hdmi_safe=1
• config_hdmi_boost=4 7, 11 I changed the HDMI cable to 1.5 meters as well

Once I don't remember which settings I had, I got a signal, but it was just for a one second followed by several seconds black screen and these two states were repeating, but of course not usable.

Here some debugging info:

$ tvservice -s
state 0x12000a [HDMI CEA (16) RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive

$ tvservice -n
device_name=DWE-HDMI

$ tvservice -M
Starting to monitor for HDMI events
[I] HDMI cable is unplugged
[I] HDMI is attached

$ tvservice -m CEA
Group CEA has 15 modes:
       mode 1: 640x480 @ 60Hz 4:3, clock:25MHz progressive
       mode 2: 720x480 @ 60Hz 4:3, clock:27MHz progressive
       mode 3: 720x480 @ 60Hz 16:9, clock:27MHz progressive
       mode 4: 1280x720 @ 60Hz 16:9, clock:74MHz progressive
       mode 5: 1920x1080 @ 60Hz 16:9, clock:74MHz interlaced
       mode 6: 720x480 @ 60Hz 4:3, clock:27MHz x2 interlaced
       mode 7: 720x480 @ 60Hz 16:9, clock:27MHz x2 interlaced
(prefer) mode 16: 1920x1080 @ 60Hz 16:9, clock:148MHz progressive
       mode 17: 720x576 @ 50Hz 4:3, clock:27MHz progressive
       mode 18: 720x576 @ 50Hz 16:9, clock:27MHz progressive
       mode 19: 1280x720 @ 50Hz 16:9, clock:74MHz progressive
       mode 20: 1920x1080 @ 50Hz 16:9, clock:74MHz interlaced
       mode 21: 720x576 @ 50Hz 4:3, clock:27MHz x2 interlaced
(native) mode 22: 720x576 @ 50Hz 16:9, clock:27MHz x2 interlaced
       mode 31: 1920x1080 @ 50Hz 16:9, clock:148MHz progressive

$tvservice -m DMT
Group DMT has 14 modes:
       mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive
       mode 6: 640x480 @ 75Hz 4:3, clock:31MHz progressive
       mode 8: 800x600 @ 56Hz 4:3, clock:36MHz progressive
       mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive
       mode 10: 800x600 @ 72Hz 4:3, clock:50MHz progressive
       mode 11: 800x600 @ 75Hz 4:3, clock:49MHz progressive
       mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive
       mode 17: 1024x768 @ 70Hz 4:3, clock:75MHz progressive
       mode 18: 1024x768 @ 75Hz 4:3, clock:78MHz progressive
       mode 32: 1280x960 @ 60Hz 4:3, clock:108MHz progressive
       mode 35: 1280x1024 @ 60Hz 5:4, clock:108MHz progressive
       mode 36: 1280x1024 @ 75Hz 5:4, clock:135MHz progressive
       mode 47: 1440x900 @ 60Hz 16:10, clock:106MHz progressive
       mode 85: 1280x720 @ 60Hz 16:9, clock:74MHz progressive

• raspberry runs with 3 amps and rasbian-stretch
• display controller runs with 12 volts, 3amps (as recommended)