Hello,
Today I tried my old WaveTek Model 171 function generator/Synthesizer after 2 years of storage in a cellar, and a move to my new apartment, and the duty cycle of the output signals was
completely wrong. First I thought probably a power regulator inside the unit failed again as it happend once in the past, but after double checking all the supply rails I saw that the were all
ok.
After knocking around a little on the top board I found the problem: microchip IC5 seems to have a bad contact in its socket. Probably corrosion. IC5 forms the positive and negative current
source which then is used for signal generation inside the unit by charging and decharging on capacitor. After knocking on IC5 the duty cycle of all the signals was perfect again.
My function gen and "repair" is probably not the most exciting thing, but I thought I add some pictures here, in case somebody is interested in it. The generator comes with a nice digital
"frequency" dial in function which is used here.