GGG Phase 100 don't phase

[electricstorm]

The right most vactrols gave me fluctuations through the volt meter.

These should be working then.

I will test the trannies with a volt meter next.done,the collectors fluctuate.

Your LFO should be working. If you were getting fluctuations on the vactrols, the LFO is working.

So this leaves the vactrol on the left (this should be OC1 or VR1).

The first vactrol on the lower left has continuity but the other 2 do not.

Was there continuity in both directions on this vactrol (LED side reversing the leads to check each direction)? There should be no reading in one direction and a reading when the leads are reversed (or vice versa). If it gives a reading in both directions (when it's out of the circuit) then it is bad. Like Jon said, you don't want continuity. If the other two vactrols are good, you should have some (maybe small amount of) phasing.

Could you post your voltages again since you replaced IC1? You should have fluctuating voltage on the following ICs that are controlled by the vactrols:

IC1, IC3 and IC5 - Pin 3

IC2, IC4 and IC6 - Pin 5

Your pin 8 voltages seem too low on all the ICs.

Jim

[jimilee]

Well sure, I'll do that tonight after work. I really appreciate your help, knowing this was a bone headed move on my part. I'm not too stressed about it. It's a neat challenge to find out what happened, and a great learning process.

[jimilee]

Woops! waited a couple of days,so here we go.
IC-1
1 4.5      8 9.1
2 4.5      7 1.3-8.4
3 4.0      6 3.7-5.5
4 0         5 3.2-5.5 

IC-2
1 4.5      8 9.0
2 4.5      7 4.5
3 4.3      6 4.5
4 0         5 4.5

IC-3
1 4.5      8 9.0
2 4.5      7 4.5
3 4         6 4.5
4 0         5 4.3

IC-4
1 4.5      8 9.0
2 4.5      7 4.5
3 2.1      6 4.5
4 0         5 4.5

IC-5
1 4.5      8 9.1
2 4.5      7 4.5
3 4         6 4.5
4 0         5 4.3

IC-6
1 4.5       8 9.1
2 4.5       7 4.5
3 4.3       6 4.5
4 0          5 4.0

Only IC-1 is fluctuating on pins 5 and 6.

[electricstorm]

OK, voltages look better. And your LFO should be working as you said the collector of Q1 and Q2 had fluctuating voltage on it (the darlington setup). This basically feeds a fluctuating ground path to the LEDs in the LDRs. What I think is wrong is one or more LDRs have a bad LED.

I am looking at the GGG Phase 100 schematic and board layout. Assuming you have the same board, use your volt meter (negative lead connected to ground, probe with the positive lead) to find the vactrol that has 9v going to the + (anode) side of the LED. Next go to the - (cathode) side of that vactrol with the meter, there should be approximately 8.3v there. Go to the next vactrol and check the - side, there should be approximately 7.6v. Now, go to the - side of the last vactrol, there should be approximately 6.9v or a fluctuating voltage. The first vactrol that gives a 0v reading is the bad one. Replace that vactrol, then if there is still no phasing, do the procedure again to find the next bad vactrol.

If you are getting signal but no phasing, one or more of the vactrols has to be bad.

Let me know how it goes.

Jim

Edit: You may want to check both sides of the LED side of the vactrols in the steps above just to make sure there are no open traces from one vactrol to the next. Also, if you have 9v on both sides of the LED, it is bad (if it shorted). If you find this situation, check the resistor on the emitter of Q1 to see if it is burned or looks brown. I don't think it is bad if you have fluctuating voltage on Q1/Q2 collectors, but worth checking. Then you can decide if you want to replace it too.

[jimilee]

The vactrols are about 9.00 each (x3). I don't know yet if I want to spend that much on this particular circuit. I'm going to look around and see what I can find.

[electricstorm]

Were they actually bad? How many were bad if they were?

[jimilee]

Were they actually bad? How many were bad if they were?

I haven't tested the vactrols at this point but I think we concluded that it was the vactrols just from the testing we did. I haven't puled them out of the circuit to test them.