F14 HDMI port delivers no output to SONY 40" LCD TV

[barry yu]

I have an HP Pavilion dv3 AMD Tution x2 dual core, pre loaded Vista H
Premium 64bit, the HDMI function works soon as the Vista starts booting
into desktop, both sound and video works fine with Sony 40" LCD 16x9 TV
through HDMI, I installed F14 to dual boot with Vista and Vista still
still works fine with SONY TV, but will display "No sign input" when
boot up the Fedora 14, in monitor setting F14 detected the SONY TV, no
matter I configure to mirror both display or set one as extended, still
SONY TV produced no signal input message, can someone help?