Posts: 2

wont recognize external monitor

I have a Toshiba satelite m55-331 and connecting to it a viewsonic vp201s monitor [lcd]. Have connected them with a monitor cable and installed from manufacturers cd. monitor shows up in system hardware but when go to display it shows 2 monitors in settings but neither one says viewsonic and wont' let me choose the second monitor. won't accept the ''expand desktop to external monitor'' just keeps clearing the check. when I turn on the monitor then laptop the green light comes on then turns amber and get a small square in the blank screen that says no signal. should there be another item in system hardware that shows it recognizes the external monitor?   tried fn-f5 and hooked up different monitor but doesn't work.  checked bios.  other ports work.  what to do? help. thx