HP 8656B Successful Repair?

[OldVolts]

I'm about to take a look at a friend's HP 8656B signal generator.  It's an option 1 with a 2838 serial.
He reports that he can't get full output anywhere but he believes the attenuator is working.
Aside from the attenuator assemblies, has anyone had any experiences and success / failure in this arena?
Thanks,
Bill