[Heathkit] HW-101 Question

[KH6ITY at aol.com]

Our club is donating a HW-101 to a local gentleman who is badly crippled.  He 
will be  taking his test shortly and we intend to surprise him with  the rig. 
The club asked me to "fix it up" before we give it to him. I repaired  the 
power supply today. The rig itself was completely dead but was an easy fix.  I 
thought I was done. Then I ran into a problem that just has me  stumped.
1. On LSB everything is perfect.
2. On USB the receiver mutes and when I key the mic there is  no audio output 
on the scope from the mic.
3. On CW keying waveform and output is perfect but the receiver stays muted  
just like on USB when the key is released. 
4. On tune the rig works perfectly. 
At first I suspected the mode relay but I can hear it click when I change  
modes or go to the tune position. 
Any advise would be appreciated. I have the completed manual.
 
Regards & 73's   Larry   kh6ity    Brownsville, Tx.