Checked for connectivity thoroughly at a very early stage. Guess I have to do it again, this time injecting signals. But before I spend all that time, I want to know whether the converters themselves are OK....
Hi Script, happy new year! (To you all!)
Most of the components are pretty robust. Except they get fried badly.
As some of your channels work, I bet the Sony ICs are ok. On the units I had on the table, I extracted all of them to get rid of the electrolyte underneath. Then I put them into sockets. And I swear, they where set on heat so that I expected to frie one of them… But.. all of them survived
…
As you got the right signals on the Styros this section seems to be ok…
It must be something in the audiopath.
First check all audiopaths in the inputsection. If you got all channels there, you can continue with Ch1 that goes to the section U34.. It then goes into the frontpanel and then back .. Ch1 shares with the mic input. Check U35 what is a 2068 amp.. (I had a broken one here)
From there the signal goes to the area around U25… This complete section unlikely has problems as there are no elcos around there… Don‘t forget to turn up the input pots on the frontpanel.. otherwise you won‘t see a audiosignal in that area…
The section around U20-23 should be ok as well from the beginning as there are no elcos there.
Then you got your digital section in the middle.. As you wrote.. Signals at the styros look good.. This section seems to be ok as well.. (You should see the audiosignal within the signal of the upper con of the styros
)
Another tricky section is the one on the right arround U3 to U9. If there is a problem, you might not hear audio from certain channels as well.
Check this area for faulty opamps. I check the audio mainly with headphones. As soon I hear all channels there, I check the output section that leads to the ouputjacks.. as last step.
The Digiboard is another story. But you wrote it is ok. As there are not that many elcos there, there is mostly no problem.
Also, if you extracted a lot of caps and resistors, check if you did not mix up components. I just found a mistake I made on the unit I had from Ebay for a nice price and I
mixed a cap with a resistor arround U37 (part of the digital section on the analog board) that caused the unit to display a unexpected error at startup…
Unit is working now, but I have not checked it completely. (See next post
)
Also don‘t forget to exchange the elcos in the frontpanel.
and what my question is about, JFETs in the output section 
