I've been taking a stab at drawing your schematic using the technique I suggested in #16. It works pretty well but it's still time consuming to read the resistor values, verify where the traces connect and so on. So I'm stopping for now - you'll see it is incomplete. If you want to continue, I can keep plugging away. One thing that would help understanding the schematic is to label where the jumpers go, the AC supply and so on.

One thing I think is a problem is that, without the zener in place to draw the voltage down, the capacitor (C1, I think) and the LM324 powered from it may have seen excessive voltages. Hard to say, since you're seeing a low voltage on the power pins of the LM324. Maybe your parts are OK.

To eliminate confusion, when you report voltages, be sure to specify whether it was on your AC or DC meter setting (just as you did above). Most of the board should be operating in DC, other than the supply. But it is confusing with those jumper blocks heading off into space.

 

First thing to do is to measure the voltage between pins 4 and 11 of the opamp. It should be greater than 8 volts. If it isn't, then you need to focus all your energy on getting power to your circuit. My guess is that the opamp is operating in a comparator mode, so outputs will only be zero or full-scale. Until power is restored, any voltage reading of parts down line is useless.

 

Wow, awesome. Thanks for the effort. I've been out of town and just saw Wayne's work. I was walking out to my shop to trash the whole thing, but now I feel like I need to spend some more time on it. I'll verify the schematic and perhaps fill in the blanks and also post what the voltages are and what scale I'm using.

Wayne, Tell me again what program you are using for that schematic.

Thanks!

 

Wow, awesome. Thanks for the effort. I've been out of town and just saw Wayne's work. I was walking out to my shop to trash the whole thing, but now I feel like I need to spend some more time on it. I'll verify the schematic and perhaps fill in the blanks and also post what the voltages are and what scale I'm using.

Wayne, Tell me again what program you are using for that schematic.

Thanks!

I use a drawing program called Intaglio, which is Mac only I believe. But any decent drawing program is capable of similar results. I really like the layers feature that allows you to turn on and off any layer. I put the board in one, the traces, wires, components and labels all get their own layers.