Can't output to my TV after upgrading to Windows 7

Question

Everything was working in Vista. Now that I have upgraded to Windows 7, I can't output to my 1080p TV using the VGA output.

All I get is a "Incompatible mode" warning on TV screen when I output to it.

I have a HP Compaq nc8430 laptop with a ATI Mobility Radeon X1600 video card.

The TV is a Samsung LN40N81B and it supports 1920x1080, 60Hz.

Windows drivers didn't work, so I've tried downloading the latest Vista drivers from HP website, but didn't work either.

There are no pending updates to Windows.

Any ideas? Thanks.

Answer 1

Since you've explored the video card driver avenue, I'm inclined to think it may be how Windows 7 is seeing / using your external monitor (TV in this case).

What "mode" are you having Windows 7 output to your monitor? Are you extending the desktop, duplicating the desktop onto the TV or having the desktop displayed only on the TV?

I ask this because what may be happening is that your laptop display may be trying to send it's native resolution to the TV which may be unsupported by the TV so you are getting an unsupported mode message on the TV. What does Windows 7 detect your television as? Guessing a PnP display/monitor?

I would try extending or mirroring it first so that you can still see your desktop on the laptop screen and then go into the Windows Display settings (right-click on desktop, choose Display Settings). You should be able to choose the TV (External Display) and adjust the resolution there. You may also want to look in the advanced options to see if there is a refresh rate control. If so, you'll want to ensure the refresh rate for the TV is set to 60Hz.

Keep in mind that your laptop may not be able to drive 1920x1080 to your TV and drive your laptop display at the same time at it's native resolution. So, you may only get the full display on your TV when Windows is set to display the desktop on ONLY the TV. Are you also choosing the output to TV using the laptop output display key combination (like Fn-F5 or something)? Or are you using the Windows+P shortcut?

If none of that works you may need to select a custom monitor display driver for the TV (not sure what it currently shows up as) or, barring that, you may want to take a look at a tool like PowerStrip to build a custom resolution and see if that will work.

Apologies if you've tried all those things...Hope at least some of that helps. :)

Answer 2

Unfortunately it sounds like it's a case of poor driver support. Windows 7 and Vista use the same driver model but there are still some incompatibilities. So it's either hope that MS comes through with a better driver in an update or that ATI decides to make some Windows 7 drivers for your card.

Answer 3

You mentioned downloading drivers from HP, but it might be worth trying ATI's own drivers. Often times non-standard modes and TV support are disabled in WHDL-certified drivers, which is what the windows drivers and likely the HP drivers, would be.

Answer 4

I ran into this same problem when upgrading from XP to Vista. The message was that the tuner wasn't recognized and I must have downloaded 6 different drivers trying to get it to work. Ultimately, my solution was a clean install of Vista (versus the upgrade route).

Answer 5

As a workaround, you could try using a different output. Maybe S-video or HDMI, whatever the hardware allows.

Also, can you do a VGA output to a different TV or monitor?

Answer 6

try every possible screen size update drivers check your ATI control panel for output modes wait for more recent drivers when windows 7 hits stores

Answer 7

try setting both display at 1024x768. worked for me

Answer 8

I have a Samsung LN46A750 and it is very picky about the refresh rate. I've seen that Windows 7 seems to default to a refresh rate of 59hz instead of 60hz, and my Samsung is unable to use the 59hz signal.

If I manually set the refresh rate to 60hz (using another monitor to see what I'm doing), it seems to work fine until I reboot, at which point Windows 7 defaults back to 59hz...