This might be a second post, I got a weird error message the first time.
I just scanned my technical manual for the GNT 4604/5 which has many
references to
the 4601.
It does include schematics. You can find it here:
http://www.dvq.com/docs/GNT/
Bob
Many, many, many thanks! I bought a new-old-stock GNT-4604 about a decade
ago. It was so exciting to open the foil seal and --- nothing worked. I
did find the problem. It had cold solder joints on the control board. But
having the service manual means I can keep it running for years to come.
I also have a GNT-4601 so I'm doubly appreciative. Your work will not have
been in vain!
Amardeep