Fender power chorus channel switching

[pontiacpete]

This amp came in with both input jacks replaced with the standard switch craft type stereo 1/4” jacks. All the pads to the original 9 pin jacks had been blown out. I thought to myself, it would be nice to put the original replacement jacks back in place and all will be good. So I really don’t know if it ever worked properly with the stereo jacks, but I was definitely able to get CH1 working because 1 was touching 2’s ground.
Anyway, now it’s taken me forever to get both channels working. I wired the 9 pin jacks in correctly as far as I can tell. I’ll post a picture. Gone over my work many times.
I really can’t figure out how this thing works.
Can anyone explain what might be going on here? I have CH1 working but nothing comes out of CH2.

[Enzo]

DO NOT ASSUME. It may well just be a miswire in th jack restoration, But it is also possible the circuit has a problem. PLug a signal into the channel 2 jack, does the signal appear on pin 1 of U1a?

[pontiacpete]

A very very weak signal appears on pin1 of u1A when plugged into CH2. Way bigger when plugged into CH1

[g1]

I'm including your pic with the schematic numbers for the jack pins added in. The schematic is blurry as far as lines crossing, but your connections all check out good. (edit: not true, see post #26)

[pontiacpete]

G1 thanks so much for laying out the numbers to the jacks and checking my work. The schematic is a problem, not easy to read. I was hoping someone might see what I might be misreading.
Where do I go from here since there is very little to no signal on pin 1 of U1A and if the wiring is correct?

[Enzo]

Schematic isn't too fuzzy to see that the signal leaves the tip contact in the jack , goes through C1 and C2, and into the op amp. Nothing on pin 1? OK is there signal on either end of C1? C2?

[pontiacpete]

It’s the same on C1 and C2, no signal.

[Enzo]

Then look at the jack, and look at the jack end of C1, is the solder cracked or a copper trace broken. If signal won't reach C1, then it won't be [present later in the amp.

[pontiacpete]

When I plug my signal into CH1 there’s signal at C1and C2 and pin 1 of U1A, even if the Select switch is pressed or not. Is this right? There’s signal on R55. If you can see the picture with the numbers pin 2 of CH2 is directly connected to C1 and it checks out with the ohm meter. Something in the plug is shorting out my signal. In fact pin 2 of CH1 measures a dead short with pin 2 of CH2 whether or not something is plugged in either CH. This is getting very confusing.

[g1]

That is correct. In the pic I numbered, the red #s are Ch.1 jack, the yellow #'s are channel 2 jack.
Pin2 of jack 2 connects directly to C1.
Pin2 of jack 1 connects to pin8 of jack 2. When nothing is plugged into jack 2, pins8 and 7 of jack 2 are connected by the jack2 switch contacts. So pin2's of jacks will read short to each other with nothing plugged in.

In post #7 you said no signal at C1. Is that still the case? You should get signal at C1 with signal applied to either one of the jacks.

The switching arrangement of the amp, with the switching or parallel input jacks is very unconventional. It helps to consult the owners manual as to how they should work.

[pontiacpete]

I”m getting no signal at C1 when plugged into CH2 . But I’m getting signal on C1 when plugged into CH1. Is that what you are asking?

[g1]

Yes, that is what I was asking. So it is an issue with the jacks.
Plug signal into jack 2. Check for signal at yellow #2 pin from pic in post #4.

[pontiacpete]

There’s no signal at pin 2 of CH2

[g1]

Plug an empty 1/4" plug or cord into jack #1. Apply signal to jack#2. Still no signal appearing at jack2 pin2 ?

[pontiacpete]

Now there is a signal on CH2 at pin 2. I’m not sure what that means. Does this tell you anything? Maybe the wiring?