Success!
In the hope of making this information available to others, I changed the title of the thread in an attempt to make it more searchable.
Thanks to Ted, and whomever originally provided the information he quoted.
And thanks to those who participated in the older thread linked below.
I was able to figure out which capacitor was the output coupling capacitor (22 MFD electrolytic on my board) , and replaced it, using a larger one (100 MFD). The sound is much louder now. (Please let me know if using this size will cause a problem down the road.) I guess I should check the value of the cap on good board I have.
In summary (for this particular bad board):
AC buzz instead of steam sound - replaced 47 MFD electrolytic capacitor
Using a larger value seems to be OK.
Low volume - replaced 22 MFD electrolytic capacitor
Using a larger value makes the volume louder (Is this OK?)
General - resolder bad joints, and replace frayed wires.
Here is another thread from 2012 with some good information.
A picture of my board, with the replaced capacitors labeled is below.
Cap A - fixed the AC buzz - 47 MFD
Cap B - fixed the volume - original 22 MFD, replacement I used - 100 MFD
