monitor problem

[sebycot]

i have a problem with my laptop
i have a sony vaio(with a busted lcd screen) that i am using with an external crt monitor
the problem is that when it boot, just after "...starting X-Windws..." my monitor stops receiving any signal(the LED goes yellow)

anyone know how to fix this???
thanks in advance

[sebycot]

i test it with another monitor and it works, it even works if i switch to console mod(my monitor)
so how can i make it work properly with my monitor?