Two years? You have more patience than I do!
A question - are you trying to get sound from the DVD player to come through the TV speakers or through the speakers connected to the Pioneer?
There are three things to check:
1. That the DVD player is set up to output audio over HDMI (page 20 of the DVD-S53 manual)
2. That the HDMI input on the Pioneer VSX-920 that you are using has been assigned as the input source for audio (page 43 of the 920 manual)
3. That the VSX-920 is set up to either play HDMI audio through it's speakers or through the TV (pages 40-41 of the 920 manual)
That's to get the ball rolling. Please let us know if that does or does not fix it.