Difficulties getting the BeagleBoard to output 720p HDMI


I started playing with the Angstrom 2.6.28 console-image + SGX GLES driver and ran some of the tests provided with the SGX SDK, outputting a DVI signal to my computer LCD display. Strangely enough, the image is slightly too large to fit entirely within the display area of my monitor. Also, when I try to hook the BB to my HDMI TV (Sharp LC-19SB25U), the TV shouts “Not compatible with this signal”. I tried various flavours of omapfb.video_mode (such as 1280x720MR-16@60), some of which I tested using my TV as a secondary display for my computer, but to no avail. Also, when I set omapfb.video_mode=720p60-16 which some people here reported having used successfully, the bootup hangs with those lines displayed last:

Console: switching to colour frame buffer device 80x25
clock: clksel_round_rate_div: dpll4_m4_ck target_rate 48000000
clock: new_div = 9, new_rate = 48000000

Now, I’m really wondering why I’m experiencing this uncommon issue and if there is a way to get my BB to output a digital signal that is compatible with my TV.


There are several threads about this. I managed to get things working
with 2.6.29 and setting videomode to hd720 (or was it 720hd).
I also needed a patch to invert the sync.


The issue is not uncommon. You can apply the patch at:

and set "video=omapfb:mode:720p60" in your bootargs. This worked for


If you want just to check really fast if everything is working the
following modeline set the output at 720p60:

dvi e:1 u:1 t:0 h:1280/220/110/40 v:720/20/5/5 p:74000

just echo that on /sys/devices/platform/omapfb/displays if you are
using 2.6.28 from angstrom demo.

For other kernel versions and patchset the path and format of /sys
files may change, but the numbers still apply.


Hello ,

Take a look at a post at this URL for some pointers


If you still have trouble, repost a message here...



First, I wish to thank you all for your help. I tried to echo the
modeline as you suggested but unfortunately, I was unable to get rid
of the nasty "Not compatible with this signal" message. Below is the
EDID I extracted from my Sharp TV using a tool called Monitor Asset
Manager. The "Standard timings supported" section is empty, can it be
the source of my problem?

  Model name............... SHARP HDMI
  Manufacturer............. Sharp
  Plug and Play ID......... SHP1004
  Serial number............ n/a
  Manufacture date......... 2007, ISO week 0