[R-390] R-390A EAC Crystal Osc Issue

[Byron Tatum]

Just a note here-   Was servicing some later model 67 EAC units and found a common issue amongst these with the crystal osc module crystal sockets. This is the module with the phenolic framework that gold colored heater cover attaches to with 4 of #4 screws.   It seems the crystal socket pins become spread and lose contact. I know these units were not messed with much at all so this loosening of socket pins occurred on its own through other processes (shock, vibration, ?). Have noticed that some of the crystals have a pin bent slightly, presumably done by a previous owner to address the problem.   I did not try to compress the socket (female) pins to make them tighter. I made sure on the loose fitting ones that the slight bend in crystal pin was in correct direction; ie not going toward the separation in femal pin. Also I cut a piece of insulation about 1/4" thick, very much like found existing one under oven top cover, to apply more pressure to rows of crystals to help maintain good contact.   I was having trouble with losing crystal oscillations and thought at first I needed to look at sync adjustment of switch shaft however that was not the case. Byron W5FH