Windows 7: no sound through tv via hdmi, sound plays through laptop speakers (idt

Yesterday I installed a new external hard drive - following the installation - my sound no longer played through my television (video is fine, HDMI connection) and sound now comes ONLY through the laptop speakers.

The option for HDMI Audio doesn't appear in the 'sound' menus. I have 'checked' "shoe disabled" and "show disconnected" in those menus.
Basic Specs:

DV7-4060us

Windows 7/64bit

IDT High Definition Audio Codec

ATI Mobility Radeon HD 4250
AMD M880G with ATI Mobility Radeon 4250

I have tried the following fixes gleaned from other forum posts on similar forum posts:

Uninstalling and reinstalling IDT drivers - didn't work.

HP driver 'recovery manager' to install 'original' IDT audio codecs - didn't work.

Unistalled ATI Video Drivers , and reinstalled them - didn't work

System Restore to a week ago - didn't work.

I use my HD TV as my primary monitor for gaming, so having sound through laptop speakers and not TV is quite annoying.

Perhaps my only solution is another sound card?

So you're trying to get audio to play on your TV from your laptop? Since you said the video is fine it's obviously not the video drivers. It sounds like the sound output is configured wrong. I don't think it would be labeled as HDMI. HDMI is just DVI with HD Audio. Try altering your sound settings to see what you can get.

Audio is a very difficult thing to diagnose and fix.

video and audio worked fine for nearly a year.

then I go the new external hard drive, now audio only comes through laptop speakers and video still works fine via my HDMI hookup.

See my second paragraph please - i've altered and double/triple checked all my sound settings - it is not a problem with sound settings.

The IDT audio has nothing to do with the HDMI audio, that is done from the HDMI audio built into the AMD HD 4250. Look in Device Manager under "sound, video and game controllers" and make sure that the AMD HDMI audio is showing there. If it is then check that is is working properly.

It may take re-installing the AMD driver (the HDMI audio driver is part of the video card driver package) to get it back.

thanks for the reply stormy.

it doesn't show up there - it hasn't during this whole process. that's why i already uninstalled and reinstalled ATI Mobility Radeon HD 4250 and
AMD M880G with ATI Mobility Radeon 4250 drivers twice. still to no avail (see my third bullet point under attempted fixes)...

however, that gets me thinking - I have NOT tried to roll those back to the original drivers that came installed with factory settings for the video drivers using the HP Recovery Manager. Gonna give that a shot and see what happens.

One more place to look is in the bios. No idea if the setting is there seeing as it is an HP laptop, but there should be a setting somewhere in the bios to enable/disable the HDMI audio. It is possible that if there is has somehow managed to get set to disabled, as you say that it isn't showing in Device Manager either.