Windows – NVIDIA secondary display problem on Windows 7 Professional 64-bit

displaymultiple-monitorstvvideowindows 7

All of this was working fine on Windows XP Professional SP3. I just installed Windows 7 Professional 64-bit and it doesn't work anymore.

My video card is an NVIDIA GeForce 8500 GT. I have a plain old VGA cable running to my primary display (19" LCD monitor). I have an S-video cable running to a Philips RF Modulator (model ph61159) pictured here:

Philips RF Modulator (model ph61159)

Philips RF Modulator (model ph61159)

From the "TO TV" coax jack on the back of the RF modulator, I have a coax cable running to a splitter that sends the signal to all of the TV's in my house. So when I wanted to watch a computer video on one of my TV's, my process was:

  1. Enable the secondary display.
  2. Drag the video to the secondary display.
  3. Turn one or more of my TV's to channel 3 or 4 (depending on the RF modulator's front switch)
  4. Enjoy.

See the little red LED on the front of the RF modulator? It's supposed to turn solid when I have the secondary display enabled. It's off otherwise.

Before installing Windows 7, the light would turn on as soon as I switched on the secondary display in either Windows Display settings or using the nVidia control panel (either way worked).

After installing Windows 7, the light will blink a little bit when I switch on the secondary display in either Windows Display settings or using the nVidia control panel, but goes off and ultimately I have nothing sent to my TV's.

Here is a video of what is happening.

This is a show stopper for me. I will reinstall Windows XP if I can't get this fixed. Is there anything I can do?


I had my wife watch the tv while I turned on the secondary display and she saw windows on the tv for a moment, but then it disappeared.


I changed the refresh rate for the TV from 29hz to 30hz and that gives me a solid red LED on my RF modulator, but the TV has a black & white picture that isn't still (moving from top to bottom very quickly.) I haven't found any more advanced settings yet. Any ideas?


I noticed that when you change the tv's refresh rate to 30hz and press apply, the refresh rate changes to 25hz, which wasn't in the list of options before.


At some point I had a still black & white picture on the TV, but I have no idea which combinations of nvidia control panel settings and windows display settings got me there.

Best Answer

Have you tried the "My display is not shown..." option on the page that you showed in your video? There is an option to force detection of TVs that might help.