I have a schematic of the origin 20, is almost the same.Ok, my guess is that valve isn’t drawing any HT current.
Hence it isn’t working and so not passing any signal.
It would be a good idea to investigate that.
Without a schematic I can’t be more specific unfortunately.
The voltage at pin 3 is 74VThat drawing shows the V2 pins1-3 section as a cathode follower, so the pin1 anode voltage will be higher than normal due to the absence of an anode load resistor. What’s the pin3 voltage?
I have the voltagesPin8 shouldn’t be 0V.
How about a full voltage survey, every pin of every valve.
Be careful, it’s much better to use probe clips on valve sockets and terminals etc, that can help to avoid the probe tip slipping off the terminal and shorting stuff.
R54 is not shorted. And there is no resistance between pin 8 and 0V.Is R54 shorted?
eg what’s the resistance between V2 pin8 and 0V common?
If not, maybe a bad connection, eg failed solder joint somewhere in that area. Generally need strong lighting and visual magnification to see that kinda stuff.
Hi, I am sorry, there was a thick layer of solidified flux on pin 8. is clean now.I’m confused, can’t make sense of the above, seems contradictory?
I have made a video to show how the amp reacts when touched with probes on the pins with high voltage.I’m confused, can’t make sense of the above, seems contradictory?
In most places, resistors can be measured fine in circuit. No necessity to lift one leg.I learned now that I need to disconnect at least one leg of the resistor to accurtelly mesure it, do I need to do it with all the resistors?
I can’t make sense of either of the above points.Because the values are all ok and R63 in circuit mesures 0ohm and of circuit mesures the correct value.
Also mesured 1,8Amp around R58, that is a 1w resistor, but is visualy ok and the multimeter says the resistor is ok too.
Maybe the fx loop switching is bad, have you tried plugging a cable between send and return?V1 almost no sound V3 very loud sound
The resistance at R63=47k ( in series with C37 and pin 8 of V1), read the same resistance the same as a short piece of wire when in circuit.In most places, resistors can be measured fine in circuit. No necessity to lift one leg.
Occasionally there will be parallel resistive paths, and the measured value will be lower than the nominal value of the colour coding. In that case the schematic and some basic circuit analysis will indicate whether the measured value is reasonable / whether further investigation (eg lifting a leg) is called for.
I can’t make sense of either of the above points.
By 0ohm, do you really mean 0ohm, same as a short piece of wire, or do you mean infinity, an open circuit?
Each clause of the second sentence needs to be explained in detail.
When referring to a component reference number, eg R58, it’s helpful to also describe where it is in the circuit, eg V1 pin1 anode.
Given the fault, a full, readable schematic is pretty much essential to help you any further.
Maybe the fx loop switching is bad, have you tried plugging a cable between send and return?
Have you eliminated a bad valve as being the cause of the issue?