There appears to be no solution to this problem as posted. I spent a lot of time with Dell on this. The bottom line went something like this......
- XP design, development and significant support releases preceeded HDMI
- Because HDMI integrates audio and video (and probably because of a lot of other security and copyright BS) it requires support of not only the audio (IDT) driver but also the video (Nvidia) driver, plus the OS (XP) all the way down to the BIOS.
- I lot has been learned about the issues with HDMI and all the interractions between these parts over the insuing years and even to this day they are still making changes even down to the BOIS level of computers to handle HDMI properly.
- These changes necessary to take advantage of the learnings and improvements are no longer being made to XP
- Not suprizing, at the driver level, the changes are not being made to XP (audio and video) drivers to fix things either,
- In fact it appear the IDT audio driver for XP doesn't work properly at all with HDMI and doesn't even appear to support HDMI.
- The Nvidia driver is a little better. They at least made an attempt to support HDMI (including sound) at some point and for the "most" part it works. However, there are features you would expect there also that seem to be missing, plus it links back to the broken IDT driver....
- Upon further research I learned that the Nvidia driver that Dell uses for XP on the E6520 was not written for the video chipset used in the E6520. It is a generic driver from a long time ago (2008?). If you go to the Nvidia site, they do not have an XP driver for this chipset. They reference the old generic one. So, perhaps this is not entirely Dell's fault..... Its a question of where you think the buck should stop..... Dell... Nvidia....Microsoft....
- The bottom line comes back to the fact that XP predated HDMI and Microsoft will never bring it up to date to support it completely... so no one else worries about fixing the problems (Nvidia, IDT, Dell) and who can blame them. XP is two generation old. Technology marches on.... Windows 7 is where its at.
- Hence the so so support of HDMI when using XP on the E6520.
OK..... so much for the bad news. Here is the good news. If you follow the practices below, sound will work. You may not have all the fancy sound settings and features you when you use Windows 7, but it works.
- Understand upfront that the computers control panels (Volume Control, Sound Control Panel and Video Control Panels) change their features and options depending on whether an HDMI device is attached and turned on or not. Don't be confused by this. I was. Don't look for things you saw when the cable was detached or TV turned off that you saw when it was connected and on.
- With HDMI cable detached, click on the speaker icon in the task bar and under Volume Control panel Options/Properties settings you see the mixer device it is set to IDT Sound with no other choice. That's fine. That's how it looks when HDMI is not connected. Close the sound control panel.
- Connect the HDMI cable to a monitor/TV and turn it on and you should hear the sound of the computer recognizing the HDMI connection/monitor. This should cause the sound driver to switch to Nvidia (and control panel options will change too). Verify this by clicking on the speaker icon in the task bar again and under the Volume Control panel Options/Properties settings note you should see multiple devices now all set to Nvidia with IDT Sound as a second choice. Leave it set to nVidia. That's good. If the playback device isn't set to Nvidia it is a problem. You may be able to change it to Nvidia here, but to get it to stick, you may have to go to the main Control Panel and open the Nvidia Control Panal and set the Sound Device to Nvida there. Note that you can only see the Nvidia sound device options when the HDMI cable is attached and the monitor/TV is on.
- With this done, sound will always work with XP and HDMI if do things in the following order....
- Reboot your computer
- Turn on your TV/monitor (and don't cycle its power later, it is the same as disconnecting a reconnecting the cable later)
- Connect the HDMI (very important this be done before opening the browser or video player and trying to play a video)
- Open your browser or video player
- Start the video
- Do not cycle power on your monitor. If you do (or it times out and shuts off by itself) you need to at least shut down the video play or browser and turn the monitor back on with the HDMI cable connected before you fire up the browser or video player and start the video.
- If you made the mistake of starting the video with sound before the other steps..... forget it.... too late... you won't get the sound through HDMI. Start over.... You may not have to go back and reboot, but sometimes I had to.
- Windows 7 has full support of HDMI by all the players. If you can use it, do. You will get a lot more options for HDMI sound settings and can set the HDMI as the default output for sound.
As for the IDT driver under XP supporting sound or working right..... it appears hopeless.... at least from everything I found.
I hope this all helps.....