So we got another solid 2.5 hours of work last night. The good news is that everything we checked has correct voltages running to it. Everything “works”, except no sound (and one new issue outlined below). I can’t remember the name/type of chip but there’s a 14 pin chip that has different frequencies running out of it and all of those checked out ok with the oscilloscope. The last part we tried to check was the actual audio output and had some trouble with the scope. So today dad will be following up with the scope and making sure we were using it correctly. That’s a new item for him (though he used one back in the day).
One thing I noticed was that with the keyboard turned all the way up, and the very small Dell computer speaker we plugged into it also turned all the way up, the “noise” I can hear when the speaker is held up by my ear changes a bit as I switch switches on the keyboard. Also, if I start the arpeggiator I hear “noise” changes at regular intervals. So it seems like something is happening.
The new fault we found last night was that the membrane pad no longer works when we press the 1, 2, 3, and 0 keys, and there are a few of the function buttons that don’t light up also. AND the LCD display is missing the very bottom row of lights. So the number 8 looks like a capital A.
The weekend before we started troubleshooting my friend (who is the actual owner) wanted the Gligli mod installed. Since there is no soldering required I performed that operation on my own and the keyboard worked as expected afterwards. But given my unfamiliarity with the new control scheme with Gligli I’m considering putting the factory chip back in for now while we continue to troubleshoot.
So, there’s the update. We’ve not had any victories yet and keep taking steps back it seems, but we’re not discouraged yet and will get back in there this evening. As always if anything I’ve mentioned sparks an idea please feel free to share.
And I realize this isn’t the most “technical” explanation but it’s the best I can do as I’m in the process of learning more…