Dual monitors -- main one is blank on startup

[ptitterington]

Hello,
I have an annoying problem and some advice would be appreciated.
My office work PC is a Dell Vostro 410 win 7 and pretty up to date.
ATI raedon 3600 driver 8.850.0.0.
Main monitor is a viewsonic connected to graphics card with a cable and adapter to fit a socket that looks like HDMI but not quire. second monitor is old samsung 17in.

For quite a while when I booted up the main screen was black, if I turned it off and on while wiggling mouse and then quickly clicked a file it would stay on. Last few days when I turned on and off I got a brief glimpse of the desktop before black again.
I have unplugged monitor 2 and the main one works just fine.

Any Ideas much appreciated as I have got used to using 2 monitors and this is a pain.
Ta

 

[DKRON]

What happens when you boot into windows with only the main monitor plugged in then plug in the second?

 

[ptitterington]

Ok thanks for the reply, I have been experimenting and for a while thought my main monitor was dead.

I connected main monitor only via DVID and othen not connected for a few days was fine then same problem, got a flicker when turning on and off by power butten but would not come to life.
So I lived with small monitor via DVID connector for a few days.

With some experimenting, all now works well for last few days with this;

Main monitor connected to Display port with adapter from DVID cable.
Second monitor connects to DVID port via a SVGA cable and adapter!

Why??!

 

[ptitterington]

Update,
This morning, main monitor not on again after boot up, fortunately came on with switching monitor on and off while moving the mouse and clicking on the desktop.

Surely it is either the Graphics card or the monitor and I am guessing monitor!

 

[DKRON]

Main monitor connected to Display port with adapter from DVID cable.
Second monitor connects to DVID port via a SVGA cable and adapter!

Why??!

Are you connecting one monitor via graphics card and the other via onboard video because that would be causing your problem, your computer will be switching back and forth fighting for visual control. also i would never run vga to dvi, it won't look very good

 

[ptitterington]

Both from the same graphics card.