Zenith MJ1035 - no sound

[Jeffhs]

I was working on my Zenith MJ1035 stereo FM radio tonight, trying to get more volume from it (the volume control is intermittent and is now to the point where it will not vary the volume level at all, although it did work well enough that the radio was playing at reasonable volume before the problems began). I looked under the chassis and found the ground connection from the volume control housing had come loose. I resoldered it, connected the other end of the lead to the chassis, and tried the radio again. This time, nothing but hum from the speaker. I worked on it for several hours tonight trying to find out where I am losing the signal, to no avail. Any ideas?

Thanks in advance.