Harmony H306: no output

[MarkusBass]

The connections can be identified (see below components for Input #3 and #4) although some details are not visible (like e.g. cathode resistor and its connection to the ground).
Since the problem is common to both channels, this may be something more sophisticated like missing ground, or incorrectly wired volume pots. But again, this can be easily verified even by tapping with a finger on volume pots and measuring few voltages on the first tube.



EDIT: what worries me is that Input #1 and #2 are connected with 220k resistors while it seems to me that they should be 100k (at least this was the value used in 307). But this cannot cause that the signal is missing.

[52 Bill]

Mark: Thanks for the new photos with the added descriptions. What I can't see is the connection to pins 4/5 on the first tube. I see the orange wire going over there, but I can't tell what it connects to. The brown wire appears to connect to pin 9.

The schematic that I saw shows two inputs with 33K mixing resistors and the other two with 250K resistors. Both connect with 0.005uF blocking/serial caps.

[g1]

Is this the schematic and parts values you are all using?

[MarkusBass]

What I can't see is the connection to pins 4/5 on the first tube.

You may be right. If I do the same exercise with the second part of the first tube, I can identify all the components but I cannot tell where exactly is the orange wire connected. It looks like it is connected to pin #6. So we are back to the quality of the photos and some basic measurements of the first tube.
Jonny, can you clarify the connections to tube #1? Is the orange wire connected to pin #6? Is the resistor connected to the pin #6 grounded? Have you managed to make basic measurements of the first tube?

Mark

[MarkusBass]

Is this the schematic and parts values you are all using?

I think this is this one. R1 and R2 are 100k but this is not important at the moment.

[52 Bill]

This is the one that I found.

[g1]

What seemed a bit odd to me in both diagrams is the single "open circuit" input jack. But I can't see any way the jacks could be wired up so that none worked, or so that plugging in to one at a time would suddenly allow it to work.
So in agreement with the possibility of a ground fault or charging/discharging issue in the input circuit.