So it has finally happened, both the LD and DVD tray refuse to open. When I turn on the system "open" appears on the read out and I hear a lot noise from the unit but nothing happens. I'm assuming it needs a belt replacement. Any suggestions on how to repair this badboy?

You have to open it up and verify one of the pickups is in the rest position on the bottom rail, if it is then press open and try to help lift up the laser assembly. If that does not help then you have more serious issues, like maybe the ribbon cables and Pioneer no longer stocks the cables for the DVL-90 or DVL-700.

Possible problem a broken cam gear... or simply a loading belt.