Get the documentation. Get a book on basic electronics, then start doodling around in there.
Measuring electronic components in place with a multi-meter is a study in futility.
I'm just watching a few Fluke 114 meters....they're listed as True RMS.....will they be ok?
The leads from the DBX units only have multipins on one end....the other end is moulded into the units themselves. Because I don't know what happens at the audio interface multipin it's difficult to know where the signal is dying. The signal 'dies' when DBX is engaged on Channel 8....does that mean the switch or switching circuitry is to blame? Actually it can't be, because when the DBX multipin leads are switched, the problem jumps to channel16 and the DBX unit now receiving audio from track 16 is fine....so it must be somewhere in the audio units circuitry or the multipin backplate (I think?????).
It appears I have all the documentation, according to Jo at Tascam UK. There is no other documentation other than the 'Operation /Maintenance' manual, of which I have a PDF. There doesn't seem to be anything in it though that documents the wiring from the audio box to the DBX units......this would mean trying to build a 'bridging connector' (jumper sockets) would require reverse engineering the socket from the backplate (if like others one wanted to run the MS16 without the DBX units).
Do you mean I should remove suspected components and try measure them out of the board?
The dBx cards can be worked on and made to work and the one on the last track should be moved to the center tracks to make sure you are just not dealing with tape edge damage or effect. There are two of us Teac people still working on equipment such as Russ in New Jersey and myself (Sam Palermo) in the Chicago area. Contact me if you need actual address information. I also answer questions by E mail and on forums.
I operate Skywave Tape Deck Repair.