Flashing Orange LED (Xbox Original)

If you get a flashing orange light on the Xbox Original, it is a pretty good indicator it is the AV cable is not connected or bad.

There is a potential the SMC (a PIC chip that handles low-level control and AV cable detection) is bad, but it is much more likely you just have a bad AV cable.

If you do not have a cable present, you can just ground pin 19 for example to set the cable detection into outputting NTSC Mono and bypassing the orange flashing light.