no signal with catalyst drivers on hd tv (radeon hd 5700)

hi...
I did use a crt up untill today, an iiyama vision master pro but i decided to switch to using my hd tv instead since it's bigger. so i turn it on and get no signal. No problem i thought, booted in safe mode, removed the ati driver and rebooted.... booted fine and the system driver allowed me to change resolutions. I redownloaded the ati driver, installed it and restarted, but again i get the no signal thing, i assume it's trying to use some crazy refresh rate that i would have used on my crt.
Anyone got any ideas how i can get catalyst on here and still actually be able to see the screen?

its got a normal monitor socket, im using that. I have sort of managed to get it working now. I'm using the TV atm though im not able to change settings without it going out of range again. Also, when i try to change a setting and it doesnt work it doesnt reset back to previous config even if i dont press anything, it just stays out of range and i have to go get the old crt, plug it back in, uninstall catalyst, reinstall then switch the cable over to the TV. I cant even use the detect monitor function as that sends it out of range too.