Dok,
Thanks for the comments and re the soldering, I have spent a lifetime with a soldering iron (currently have three of various wattages) and I would suggest that my lungs are fuller of solder smoke than the world's greatest chain smoker and what space is left is prpobably filled with fiberglass strands !!!!!!!
Problem with doing the plug is that I can see absolutely no way of breaking it fully down so that I can get to and identify the pins from the rear of the plug.
I have just spent about the past 2hrs stripping down as far as possible the plug and stripping the outer plastic cover and the earthing braid about 1/2" and cutting off the braid and fully inspecting the cable inside the plug to ge sure that all was intact, etc and then using electricians tape to bind everything and finally wrapping two layers of heat shrink as a wrapping on the outside (I also pushed the heat shrink up inside the plug to give better isolation), then very carefully replaced the holding clamps and finally re connected the plug to the rear of ther desk, ensuring that everything was tight. I still do not understand why the earth braid is not earthed at at least one end, because as it is, it is acting as a super RF aerial --- it should be earthed at the desk end in an audio situation.
I then powered up, spoke into the mic (OK) then with only one OPT-8 card in circuit (other two inserted but not light pipe connected to the desk), checking the clock on both the desk and HD24 and raising the faders on the Tape Bank, I hit Play on the desk, the recorder started, but there was no audio and no VU readings (the song has about a 7 sec silent intro, so no reading for that time period), but after about 20secs still nothing although the meters on the ND24 were operating normally and both the desk and Hd24 were counting in time sync.
Shutdown then rebooted and did this process this three times and each time the same --- no audio.
Then I decided to do something different. Shutdown and rebooted and checked the mic (OK). This time I continued to softly scratch the mic and after about 30 secs the VUs froze and the scratching audio ceased to be heard or seen on the desk and moinitor displays.
Then gave up and powered everything off.
If I really get bored during the week I will flip the desk (AGAIN !!!) and remove the base plate then see what happens on booting. If the desk works perfectly I will virtually give up because I will have absolutely no idea what the problem is !!!!!
David