I am currently trying to learn more about video signals. I'm particularly interested in NTSC since I live in North America. 

I recently bought an oscilloscope (Siglent SDS1104X-E) and I am trying to look at the composite NTSC signal output by a Playstation 1 (SCPH-101/PSone/NTSC-U/C).

Now I was happy to learn that my scope had a NTSC trigger built in, however I couldn't get it to trigger at all in this mode...

Anyway I forced a trigger and this is what I got:

[![enter image description here][1]][1]

From what I've read on NTSC the reference white should be 100 IRE (714mV) in amplitude and the sync level should be -40 IRE (-285.7mV) in amplitude so I don't understand how come my scope calculate a minimum amplitude of -12.80mV? Shouldn't it be around -285.7mV? Is the playstation generating a scaled down signal somehow?

Here's a picture when I zoom in on the signal:

[![enter image description here][2]][2]

To me this looks like 1 scanline worth of signal. So I think the signal looks fine except for the amplitude. I can clearly see the signal dropping to the sync level followed by the color burst.

[![enter image description here][3]][3]

What am I missing here? Why is the signal amplitude wrong? How can my TV even display this signal correctly?

  [1]: https://i.sstatic.net/9cQ7V.jpg
  [2]: https://i.sstatic.net/7AjoI.jpg
  [3]: https://i.sstatic.net/fbPK1.png