sgi sync on green monitor problem, not sure if its dead or not...

hello,
just got my SGI octane system delivered from a place in sydney, the monitor i have is an SGI GDM20D11 and it will power on alright, sounds ok when the tube fires up (you know the screen turning on sound)

but when i put a signal to it from my octane workstation it makes this funny buzzing sound for a couple of seconds and i get no image at all, the power light and the 'power saving' light both start blinking and the screen stays blank....

im thinking that it could be the electron gun, but im not exactly sure coz i dont know much about monitors, ive tried using the remote to reset it and try all the settings (put a new battery in)

please help me i want my monitor to work.....