I met similar issue as well. My monitor is ASUS LS221H which can correctly display outputted from my mobile phone Xperia Neo V via HDMI. From here, we can confirm the monitor and the cable both function well. After powering up, sometimes I could see the logo from BeagleBone Black. Then, what I could see is just no signal reported from the monitor.
I referenced the page, http://circuitco.com/support/index.php?title=BeagleBoneBlack_HDMI, and tried something described in the page via terminal https://192.168.7.2/ Followings are some information of my board. *root@beaglebone:/sys/class/drm/card0/card0-HDMI-A-1# xrandr --verbose * Screen 0: minimum 320 x 200, current 1280 x 720, maximum 2048 x 2048 HDMI-0 connected 1280x720+0+0 (0x42) normal (normal left inverted right x axis y axis) 474mm x 296mm Identifier: 0x40 Timestamp: 1523547016 Subpixel: unknown Gamma: 1.0:1.0:1.0 Brightness: 1.0 Clones: CRTC: 0 CRTCs: 0 Transform: 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000 filter: EDID: 00ffffffffffff000469f12201010101 20130103802f1e782e78f5a655489b26 125054bfef80b30081809500950f9040 714f0101010121399030621a274068b0 3600da281100001c000000ff0039384c 4d56443030343433360a000000fd0038 4b1f5111000a202020202020000000fc 00415355532d4c5332323148ffff01ff 02031e764b909f859484930312010716 230907078301000065030c000000023a 801871382d40582c9600da2811000018 023a80d072382d40102c4580da281100 001e011d8018711c1620582c2500da28 1100009e011d80d0721c1620102c2580 da281100009e011d00bc52d01e20b828 5540da281100001e00000000000000dd 1280x720 (0x41) 74.2MHz +HSync +VSync h: width 1280 start 1720 end 1760 total 1980 skew 0 clock 37.5KHz v: height 720 start 725 end 730 total 750 clock 50.0Hz 1280x720 (0x42) 74.2MHz +HSync +VSync *current h: width 1280 start 1390 end 1430 total 1650 skew 0 clock 45.0KHz v: height 720 start 725 end 730 total 750 clock 60.0Hz 720x576 (0x43) 27.0MHz -HSync -VSync h: width 720 start 732 end 796 total 864 skew 0 clock 31.2KHz v: height 576 start 581 end 586 total 625 clock 50.0Hz 720x480 (0x44) 27.0MHz -HSync -VSync h: width 720 start 736 end 798 total 858 skew 0 clock 31.5KHz v: height 480 start 489 end 495 total 525 clock 59.9Hz 640x480 (0x45) 25.2MHz -HSync -VSync h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz v: height 480 start 490 end 492 total 525 clock 59.9Hz *root@beaglebone:/sys/class/drm/card0/card0-HDMI-A-1# parse-edid edid* parse-edid: parse-edid version 2.0.0 parse-edid: EDID checksum passed. # EDID version 1 revision 3 Section "Monitor" # Block type: 2:0 3:ff # Block type: 2:0 3:fd # Block type: 2:0 3:fc Identifier "ASUS-LS221Hÿÿ" VendorName "ACI" ModelName "ASUS-LS221Hÿÿ" # Block type: 2:0 3:ff # Block type: 2:0 3:fd HorizSync 31-81 VertRefresh 56-75 # Max dot clock (video bandwidth) 170 MHz # Block type: 2:0 3:fc # DPMS capabilities: Active off:yes Suspend:no Standby:no Mode "1680x1050" # vfreq 59.954Hz, hfreq 65.290kHz DotClock 146.250000 HTimings 1680 1784 1960 2240 VTimings 1050 1053 1059 1089 Flags "+HSync" "-VSync" EndMode # Block type: 2:0 3:ff # Block type: 2:0 3:fd # Block type: 2:0 3:fc EndSection *ID.txt* Cloud9 GNOME Image 2013.06.20 *root@beaglebone:~# cat /proc/cmdline * console=ttyO0,115200n8 video=HDMI-A-1::640x480@60 root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait Finally, the three steps below work like a charm *root@beaglebone:~# export XAUTHORITY=`ls /var/run/gdm/auth-for-root-*/database` * *root@beaglebone:~# export DISPLAY=:0.0 * *root@beaglebone:~# xrandr --output HDMI-0 --mode 1280x720 --rate 60* *root@beaglebone:/sys/class/drm/card0/card0-HDMI-A-1# fbset* mode "1280x720-0" # D: 0.000 MHz, H: 0.000 kHz, V: 0.000 Hz geometry 1280 720 1280 720 16 timings 0 0 0 0 0 0 0 accel true rgba 5/11,6/5,5/0,0/0 endmode After these, I do see the output on my monitor. But anyone can tell me, if I tried optargs=video=HDMI-A-1:1280x720@60 in uEnv.txt The result is still no signal? Thanks honercek -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
