A complete guess (and that's all it is) would be that the center might be your problem. I'm not claiming that what you've mentioned (connecting pre-amp outs to the line level inputs on your TV) would be wrong, but I'm just wondering if the impedances would correctly match. You might have a superior TV than I do, so I'm just thinking out-loud referencing my own system. I think this is how it works, again, don't quote me on it.

You pre-amp out on the 1050 vary output voltage, whereas a VCR or something like that wouldn't. My TV has its own amplifier inside, so I'm assuming you are setting the TV volume level to some constant and letting the volume control on the 1050 change the volume of the entire system. There could be a difference in impedances, which would then send the power from the pre-amp outs out of their range, causing a shut-down to prevent destroying a circuit. Power= Current^2 * Impedance, so if there was some sort of difference between an amplifier's input and a typical line input, that could be the issue. But I could be 100% off base and/or your components might be designed correctly to perform that way.

I would suggest, as a quick check, unplug the center channel pre-amp out and turn off the center channel in the 1050. Crank it up and if it does the same thing, you've eliminated the possibility of that being the problem.

For what its worth. . .

S.