Its just a PS3...you don't have a gaming network to play on so its ok. Just sell it for half of what you paid for it and go buy a new Xbox360.
Why go waste money on a Xbox that will break in 2 years?
You have to set it on a certain imput or channel. On my TV normal cords are Input 1, The next Input 2, and so forth. So try that. I believe for HDMI its input 3, I have the one under HDMI but above the normal cords cause my TV cant do HDMI. Im fairly sure it works the same with monitors.
And yeah its funny, because xbox fanboys talk smack about PS3, yet Xbox went down 2 weeks after first release and have almost a 50% failure rate within the warranty period. Xbox also was code broken within 2 weeks of release, it took like a year for PS3.
-BigBOBCH