What's wrong with V3?

[fugezii]

As you can see, the voltage of P1 and P3 in V3 is very high. Can anyone tell me what's wrong? Thank

[sluckey]

Wiring error(s). Pin 3 and pin 8 should be the same since they should be tied together.

[fugezii]

Wiring error(s). Pin 3 and pin 8 should be the same since they should be tied together.

I checked, there is no problem with the wiring of v3, I am sorry to forget to modify the pin8 value, it is the same as pin1.

[pompeiisneaks]

Still a wiring error. V3 (Phase inverter) cathode (pin 3 and should have small volts DC on it, like maybe 10. Are you sure you're not measuring AC volts? the signal is pretty strong at that point normally but I still don't think it should be that high. Seems like you've accidentally sent high voltage to the cathodes, or your coupling caps are leaking DC somehow?

~Phil

[sluckey]

Still a wiring error. V3 (Phase inverter) cathode (pin 3 and should have small volts DC on it, like maybe 10. Are you sure you're not measuring AC volts? the signal is pretty strong at that point normally but I still don't think it should be that high. Seems like you've accidentally sent high voltage to the cathodes, or your coupling caps are leaking DC somehow?

~Phil

That LTP PI will have a very healthy voltage on the cathodes. It's not uncommon to see 60V on some LTPs.

[sluckey]

Wiring error(s). Pin 3 and pin 8 should be the same since they should be tied together.

I checked, there is no problem with the wiring of v3, I am sorry to forget to modify the pin8 value, it is the same as pin1.

Really!

[martin manning]

The triode connected to pins 1, 2, and 3 is not passing current. Could be a failed plate resistor, grid shorted to ground, cold filament, or ?

[wpaulvogel]

A good picture of the chassis with the tube socket, wire and board would be helpful. Something like this.

[wpaulvogel]

It has a symptom of the cathode pin 3 being open circuit, not connected to ground.

[fugezii]

I found it! Pin 1 on the v3 tube is broken! Thanks everyone for their help