everything on I/O board is fine; disconnect from main board and problem goes away
Here's what I've done so far:
removed all ICs and replaced 1 by 1 to find where the problem was originally when I had 3.6V on the 12V
Q26 was bad
IC9 was bad
I replaced IC 9 and got an increase from ~3.5V to about 10.5V on the 12V rail
Here's what I'm getting
resonance pot changes pitch ( )
cutoff pot does nothing
pitch pot does nothing
envelope/accent pots do nothing
I hear "notes" that sound like the appropriate waveforms, but terribly distorted
I had it happen 3 or four times on normal boards before I started using model paint clear coat on all the traces underneath those pot legs, I think what was happening was the solder mask was thin and the edges of the pot frame sharp so you could easily short through to the trace below.
No clue why IC9 would be bringing down that rail though, nothing on the 12V is connected to that, do you get a good 5.33?
Altitude wrote:I had it happen 3 or four times on normal boards before I started using model paint clear coat on all the traces underneath those pot legs, I think what was happening was the solder mask was thin and the edges of the pot frame sharp so you could easily short through to the trace below.
No clue why IC9 would be bringing down that rail though, nothing on the 12V is connected to that, do you get a good 5.33?
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