Power MAC G4 display issues

Hi, was round a friends, bought his G4 off him after having a play around on it.
Brought it home, connected it to my tv and it boots up, chimes and loads a white screen with a grey apple, then turns light blue and loses display signal
Any ideas guys, want to get this working

G'day and welcome to the forums.

What model G4 is this - they were first released way, way back in August 1999, What sort of gfx card is installed and how are you connecting to the TV. Is there actually any operating system installed on the G4?

Hope you did not pay more than say $40 depending on the model and will your friend take it back?

Couldn't tell you unless I boot it up or do an indepth search online while looking inside. What I have done, however, is ordered a DVI - VGA converter, so will give a go, if it boots I will then find out how I can upgrade ( even if I end up getting a motherboard bundle I could use in there). I will however try and post a detailed reply to your questions when I get home, many thanks.