High plate voltage

[Strikkflypilot]

Hi.
Would loss of current i.e. bad solder to a grid connector result in high plate voltage?
I seem to have a bad contact for the left channel on my crack.
A3 led out and terminal 5/ plate power in the 170v range. Wiggling the input tube fixes it. 
I know if I am right, all i need to do is resolder or there is something wrong with the tube socket

But what do you think?

 

[Paul Birkeland]

Poke around with a wooden chopstick and see which component is causing the issue, then replace/resolder that component.

 

[Strikkflypilot]

Wood chopsticks, check.

I assume i Wont do major damage on the live circuit that way, or on myself for that matter...

 

[Paul Birkeland]

The wood will protect you, and tubes are durable enough to tolerate some abuse.

 

[Strikkflypilot]

So Ive isolated the issue to socket 3 of the noval tube socket. Its one of those teflon sockets like on the picture. Got in there with an awl, power cord out of course, and made the socket a tight fit. Now fixed. So the cathode was not connected at all. How that caused the voltage jump, I still dont understand, however.

 

[Grainger49]

When the cathode doesn't conduct, it acts like it is open, no connection to ground.  So all the voltage "piles up" on the plate.  At least that is the way I like to describe it.  It is pretty accurate to what is happening.

 

[Strikkflypilot]

I see, and it flows current only when the meter is connected, I guess.
It will take some time before I really understand these things.
Thanks for enlightening me!