Hi All,
Wow, this is one of those projects that has dragged on for ages for me...
Anyway I'm working on getting one of my units calibrated, which I'll call unit A.
Here's what I've done:
- got Igor's "original" input DOA set to read .8V between output and ground
- read -9.8V on the output regulator
- read +24v and -24v on the correct DOA socket positions
- read correct voltages on R91, R92, R93, R94
- pulled out the audio/gain reduction transistors and jumpered pins 9&10
- fed a .1V RMS signal into the unit, and measured 8V
on the output.
I'm using a JE-990 output DOA from Hairball configured to work at 24v.
While I was double checking the board, C15 and one of the 2484s on the output DOA blew out. (Loud POP from the capacitor and the 2484 is leaking some fluid.)
So... I have no idea what to do about this 8V output issue. Unit B exhibits similar behavior so I've obviously done something incorrectly on both motherboards, but I don't even know where to start looking.
Has anyone seen this behavior before? If so, did you debug it and figure out what was wrong?