ShibaSoku AM51 Audio analyzer

Congratulations. That is a very sophisticated analyzer. I have a manual for the AM70A and i can send it to you if you PM me your e-mail. The GPIB command set is probably very similar since the two instruments have similar capabilities.
 
Yeah, you are right. I have repaired already HP 8903 and Panasonic with different issues, but this one confuse me quite a lot - from changing battery and capacitance to recover PCB at digital side (some acid destroy wire bounding between logic elements). Finally it works and show attractive parameters, but I would like measure automatically like HP 8903 with GPIB.
Actually old software was made for HP8903 partially may control of this device - I can see frequency sweeping, but feedback (measured data) is different and zero level amplitude was measured continuously by this application.