Windows 7: geforce 9800gt not outputting 1920x1080 res to hdtv

nvidia geforce 9800gt
1yr old 1080p 16:9 hdtv
dvi (outfrom pc), converted to hdmi, into hdmi switching amplifier, hdmi to tv.

signal works fine under lower resolutions, but now that i've started to d/l my blu-ray i'd obviously like it to be in 1080. running windows 7, and in my resolution settings it does show 1920x1080, but when i select it, my tv reads "invalid format". i seem to be able to run up to 1360x768 as max res on this tv. tried running hdmi directly from the pc to my tv and bypassing the amplifier, same result. any idea?

Make sure the refresh rate is set to something the tv can accept and handle.

Run the latest driver from NVIDIA's site.

should have mentioned i had already installed the correct drivers off of nvidias website. had not checked the refresh rate, which is set to 60hz. i'm running a 1080p lg plasma, newer plasma refresh rate is 600hz is it not?and under the lower res it works just fine on 60hz.

Remove your hdmi switching amplifier and problems are solved.

Enjoy.

Are you plugged into the HDMI input on the TV or are you using the dedicated HD15 PC input on the TV? According to Sony it makes a difference.

I always assumed that using the DVI from the GPU to one of the HDMI-TV inputs would work best but I had resolution problems that way also same as you.

The screen did not fit the picture and I had to reduce the resolution with the custom settings to make it fit the TV screen. So I decided to actually read the directions for a change....

According to the directions that came with my Sony Bravia 52" which I just recieved two weeks ago. The first thing it said was that for a PC you need to use the PC input on the TV to gain proper resolution. This baffled me because it was the older HD15 input.

Sony also says that if you need to use an adaptor it needs to be on the PC itself, then use the HD15 to HD15 cable between the adaptor and the TV's HD15 style PC in. Resolution works out perfectly this way with no adjustments needed.

I can only assume that your TV has a dedicated PC input but it seems like most of the newer widescreen TV's have that.

great advice. picked up the lg manual, sure enouh under the pc setup section it suggests only using the dedicated rgb input on the back. who would have thought?

an odd turn. starting with dvi, upgrading to hdmi for high res video, and in the end, i have to downgrade to the old vga cable to get my 1920x1080 res. is there really no picture loss in this? how is it the old vga cables suppport 1080p picture?

Bought a dvi to vga connector, vga into the tv... works like a charm. great advice thank you chev!