Originally Posted by rabidturtles359
Tried on another TV. Same results. Input switching is fine but power cycle. When turning back on reboots it
The only explanation that I can think of, is that somehow your TV manages to avoid a "hot plug" event on input switching, but can't do that on a power cycle. Still, that theory requires the dongle to be wired incorrectly. Then again you're saying that it behaves that way on a different TV too.
A little explanation here. Per the HDMI standard, if a sink device (TV, monitor, etc) is not actively displaying content from a given input and communicating over the I2C link, the source device will assume that it will receive "hot plug" notification via dedicated pin in the HDMI cable, when the sink device is actively receiving again.
What the 360 does when it recognizes the "hot plug" event is first check the jumper settings. If it sees that 18-20 and 22-24 are present, but not 26-28, then it assumes that an HDMI audio dongle is present and then for unknown reasons, it simply resumes previous operation with no reboot. If it did not recognize the HDMI audio dongle present via the jumpers, but rather it sees a jumper config corresponding to HD component, Composite, S-Video, S-CART, etc, then it freaks out and reboots. No jumpers at all is also accepted as a valid HDMI config since it corresponds to no dongle present.
There has been some speculation that the reason for this is that the 360 thinks that someone is attempting to circumvent HDMI HDCP protection by starting up with HDMI working and playing protected content, but then plugging in an AV cable and hoping that the 360 will auto-switch to component output and allow analog component recording for protected content. This is all speculation. Only Microsoft knows why they've implemented this strategy in the firmware.
I suppose at this point, if I could see pictures of the top and bottom of the dongle with the cover removed, I may be able to see something, but honestly, if it's wired with just pins 18-20 and 22-24 jumpered, it should work. Hmmm....unless there is a problem with the hot plug connection in your HDMI cable. Can you try a different HDMI cable?