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Sometimes you need to take a bath like Archimedes.  Just looked at this for the first time since the pandemic and it was a stupid problem.  Biased up and working great.

Well, replacing both 4558s did not help.

It occurs to me, despite the weird Vs on the 324, if the rate LED is working (really blurry for the first 1/3 to 1/2 of the rate travel; hard to tell it is flashing at slower rates) can it be toast?  I mean it is a quad, so could it be only some op amps, like not the 2 involved in the rate/LED? Or is the indistinct flashing a sign of an issue? .... schem says op amp A and D are used to for rate and to drive the LED, B is unused, leaving C which is pins 8,9, & 10... which are not the droids I am looking for.  In fact pin 7 looks to be on the unused opamp B and unconnected (so it gets the expected 7.8ish volts internally somehow, which is not happening), though 12 and 13 are inputs of D which is driving the LED (if those are lower V than expected, I guess it could explain why at slower rates you can't tell the LED is flashing).  Not sure where to go from here, but I got a whole new chipset on order  so we'll see (if 12 and 13 on the 4013 are reversed in expectation - 0 vs 9 V - then is it possible the 4049 is not working right; if it is being used as an inverter that would explain it)... still stumped re the input signal, because I had it for a but whatever, the CDs pass signal so maybe it'll come out in the wash when I change those.

Hmmn, I suppose it wouldn't hurt to just check all the chip socket pins are making good continuity to the board.

Got this a while back and only just built it up this week. Test fit in the box and figured I'd test it while it's in there.  Rate light off and no signal but when I bumped it the light came on and it passed audio.  Couldn't get any flanging no matter what I did with the trim pots.

Took it out to troubleshoot and found the no light issue - rate LED leads shorted to each other intermittantly if you moved it a bit (doi forgot to tube a leg, and when test fitting I did not mount all the nuts so it had some wiggle in there). But now it won't pass audio when on (bypass is fine). Could shorting the LED have blown something?  If so I figure it'd be the LM234.  So I checked all the IC pin voltages and everything looks good with the following exceptions:

4013
12 0V
13 9 (essentially reversed)

324
7 "-0.0" on my meter

So I decided to signal probe to see where it drops.  Dead at the jack (there's continuity from jack to board, but no signal comes through the probe; thought my probe was buggered but it's fine in bypass).  Checked and it is not just shorted to ground. Checked stomp switch wiring; looks good.

Checked the Vs on the 324 again and now I am getting:
7 0V
12 varies between 1.2 and 1.7x
13 same

So I guess I blew that chip?  I don't have another on hand to sub in.

Now that would explain no flanging, but it should still pass signal like before because that's not audio path, no?  Could it have taken something else with it?  Since I can't probe signal at the I or S pads, I figured I'd try swapping out the first 4558 because I have a bunch of those, but will I just kill that too?  Pull the 324 first?

Other info:
- not using the fx loop (I remembered the jumper)
- using the J1/J2 pads  (only 1 grounded due to ground through enclosure - that's good; checked and used alligator clip to sleeve of other jack when testing out of the box) vs jacks straight to switch cuz I like top mounted jacks and it tidier that way
- quite sure I got a legit MN3007 from Small Bear but it was a while back so not 100% on that.