As far as I know, dual monitor usage doesn't impact PSU requirements. And 550W should be more than enough for your OC CPU and GPU.
Maybe you simply need to setup Windows to use the TV as a second monitor using the Display Settings.
If it seems more physical tan software, I would do some detective work:
- Test with other monitors or TV's
- Test with other HDMI cables
- Switch HDMI cables from Monitor <-> TV
- Test with the other outputs from your GPU (DVI, VGA, DP)
Good luck!