HP DV6-265us Audio :: No Sound On Internal Speakers

I have a DV6-265us laptop running MS Vista SP2. Recently, my internal Altec Lansing speakers stopped working.  First it was the left speaker, then both.  I thought for sure the speakers just died, so I ordered a replacement on EBay and just got and replaced it yesterday.  BUT, I still don't have any sound.  I can plug in external speakers into the speaker port and they work fine. 
 
Now here is the strange thing.  The speaker icon on the status bar is working exactly like it did before.  Its not showing any red X or error at all.  I can test the sound and the visual looks like its working, but there's nothing coming out of the internal speakers.  I've gone to Control Panel, Device Manager and there's not red Xs anywhere.  The device driver says its working fine, but I didn't trust it, so I did a HP driver restore and put back the original one that came with the laptop .. .Still nothing.
 
I've read the troubleshooting articles on the HP Support pages, but nothing has worked so far.  My next step is either to replace the audio board or the power button board.   I'm not sure about the audio board because I don't know how its tied into the speakers AND plugging in external speakers IS working.  It's really a sub board and seems to only have the external ports for the microphone and speakers as well as the infra-red port.  The internal speakers are plugged into the power button board and I thought that is where the problem might be since putting in a new internal speaker didn't seem to work.  The microphone is also plugged into the power button board, but that seems to be working though.