The Tektronix 5CT1N Curve Tracer Plug-in for the 5000 series oscilloscopes, similar to the 7CT1N for the 7000 series.
5Ct1N in 5440 mainframe vertical bay, X output connected to time base X input
C30 and C32 (100 μF, 25 V) have a tendency to leak or short, causing associated resistors R30 and R32 (240 Ω, 0.25 W, 5%) to overheat and fail. A good preventative maintenance procedure would be to replace these two capacitors with modern equivalents. Two 5CT1N units purchased online had this fault, and replacement of the capacitors and resistors restored proper operation.