Problem with Freiburg WIII

I am having a problem with my Freiburg WIII and I am hoping to get some sugeestions to solve it. In the attached photos, the 5Kohm resistor marked with yellow is burning up when I use the radio. I tested the circuit and the entire plate voltage for the ECH81 tube is appearing across this resistor. That is too much current ( about 4ma). This problem was intermittant at first but is happening continuously now. The radio will work for a minute or so but eventually the resistor burns up. I am hoping there is not a short in the differential filter. With the resistor disconnected I can measure about 156Kohm resistance at the + connection in the Diff. Filter to chassis ground. Thanks for any advice.

deltamike55 postete
Hi John

sth. went wrong with your uploads. There´s no pic behind the links.

Regards, Dieter

Thanks Dieter: I am still trying to figure out how to display the photos. I will try later in the day. John

I have posted the photos. Thanks for looking.

Thank you Peter: I will check that area.

Peter: Yes, I think the problem has something to with the U12 connection. I disconnected it and the radio will power up properly on FM with the correct voltage across the 5Kohm resistor when I use the FM band. However, when using MW, the voltage is quite high again with too much current going through the resistor. Do you know anything about this particular circuit that would help me to figure out the problem? Thanks for any advice. John

Peter: Your suggestion was correct. I found that U12 was getting grounded to the contact next to it which is a ground connection. It wasn't a direct short but I measured about 40Kohms. As you said it may be a carbon path. That was enough to cause the high current in that circuit. Thank you again for your help.