Need help with our hdmi cabel??????

Ok my brother has an xbox 360 and bought an hdmi just for the 360. He is using a toshiba 32' inch and I think 720p. Well it was working just fine for aout 2 months. But now it stopes. Then I bought I a ps3 and I'm using a hp 22' inch 1080p. And we tried the hdmi with the hp and it works just fine. We tried it with the 360 and the same thing. It works perfectly with the hp screen. So we tried to hook up the ps3 with the toshiba screen and it worked. So is there something wrong with the 360 or what please help. Oh and we tried to buy another hdmi but it didn't work