Okay, I managed to get the bottom half of the DP1000 removed so I could have a look inside, I think I may have found-out why the DP1000 isn't working like it's supposed to, firstly there was an IDC connector plug that came out of it's socket a bit too easily, secondly I spotted two cracked solder-joints on two of the line-out sockets, looks like it might turn out to be an easy fix.
Finally managed to remove the circuit board with all the in and out sockets on it, had a look at the solder joints and found a few more cracked solder joints, one was on one of the pins of the headphone monitor out socket, that explains why I was only hearing sound from the right channel.
Last edited by DrNomis_44; 05-09-2019 at 09:22 PM.