So i just put openelec on my appletv after removing crystalbuntu because wasn't showing a signal. when i reboot my appletv i get to the openelec logo and then after that it shows no signal from the hdmi

any ideas on what could be going on? i'm booting from an 8gb usb stick

thank you very much

i had this happen to me also with OE ended up restoring back to the atv os and resetting the video settings.

If neither OpenELEC or Crystalbuntu is able drive the TV "out of the box" you'll need to run Xorg in debug mode to capture information on the modes the TV supports then create a custom xorg.conf to disable EDID and force correct modeline settings. It's unusual, but it does happen. Earlier versions of the nVidia driver didn't like my 2009 Samsung LCD in the same way and it only in the past 3-4 months that it started working without a heavily customised xorg.conf. The key thing to realise is the OpenELEC OS is (should be) fully functional apart from the display so it's easy to SSH in and run commands to capture information and adjust things.

Start by looking at /var/log/Xorg.0.0.log to see if there's any obvious problems. If not (probably) copy /etc/X11/xorg-nvidia.conf to /storage/.config/xorg.conf and edit the Device section to add one line:
This will put Xorg into debug mode; on the next boot the Xorg.0.0.log file will contain full details of all the modes and timing data readable from the TV's EDID. Share the before and after logs via pastebin (cat /var/log/Xorg.0.0.log | paste, then visit the URL to validate it) and we'll have a look.