Mark III resistor values?

[daveg62]

I've been in the process of trying to figure out the hum problem on my Mark III. I'd like to order some resistors as some of them aren't reading correctly and I'm getting very confused as to what the values are/should be. If someone could verify, either my amp is different or someone used the wrong values before.
First the screen grid resistors - on the schematic and in most posts on the forum 470ohm and 27k should be the correct values. My Mark III has 470 ohm on the two inner sockets and 2.9k resistors on the outer sockets.
Next there are two 39ohm and two 100 Ohm resistors directly to the left of the first 30uf/500V blue filter cap at the bottom right hand of the circuit board, looking from the back of the chassis.
My amp has two 100 ohm and two 3.9k ohm resistors.
Something seems weird to me
Thanks for any help!!

 

[ltd2recto]

Regarding the screen grid resistors, 470 & 2.7K ohms is correct. 2 watts I believe

 

[daveg62]

Ok, my mistake on the 39k resistors. I didn't look at them right, they have 5 bands, duh! They are 39ohm and they are what was causing my hum problem. Both were open, replaced them and my amp is finally quiet again.
I've ordered some new 470 & 2.7k ohm resistors. They are looking kind of worn out, the 470's are starting to look black on the ends. I'm getting two different readings on the 2.7k's also so I think they are bad.
Thanks for the help.