[Boatanchors] Dear Smart People: "Zombie" 811s??

[David Stinson]

I'm working on a Collins 30L-1 amplifier. 
First time I've ever messed with one 
and I haven't done much with any amplifier. 
Had to repair the metering circuit, replace the
"fuse" resistor in the HV lead, and "Un-bypass"
all the interlocks.  This guy was asking to die.

The four 811 tubes in it look fried; discolored
plates, stained glass etc.  All the DC paths and 
high-voltage and cathode paths check-out. 
30 watts of drive on 75 mtrs gives no plate current 
and only a few watts out.  I don't have a manual;
is this amp supposed to have some idling current?
Funny... all four of the 811s test as 
"good" on a TV-7 tube tester.   I'd expect this 
would mean they so have some emission.
Is it possible they would draw current with the 
static voltages in the TV-7, but not draw current 
when driven by RF?   Are they "zombie" tubes,
being "un-dead?"