07-31-2011, 01:14 PM
Follow the B+ line and voltage divider resistors. One or more have most gone way up in value. When in doubt, replace. Cheap enough. Your voltage readings should be at or slightly above nominal values.
Schematic here
http://www.nostalgiaair.org/PagesByModel...013415.pdf
Schematic here
http://www.nostalgiaair.org/PagesByModel...013415.pdf