A curve tracer is overkill for repair work. Those who fix equipment at the
component level mostly use signal injection, signal tracing, and voltage
analysis.  Signal injection and signal tracing allow you to find the break
in the signal chain.  If the signal is good into stage two but gone at the
output of stage two, the problem is in stage two.  Now that you know it's in
stage two, you can use a dc voltmeter to find out which component is open or
shorted.  If it's an open coupling capacitor, the dc voltmeter won't help
but a signal trace will show a huge loss in signal after the capacitor as
compared to before the capacitor.  Likewise, an open bypass capacitor could
cause noise or a drastic reduction in gain but not affect dc voltages.  In
other words, dc analysis will help you find faults like open and shorted
solid state devices, but not open capacitors.  In the case of power supply
filters, open capacitors will cause a low dc voltage so the dc voltage will
be a clue in that case.

Experienced technicians switch among analysis modes as they walk through a
problem.  I have yet to see one of them use a curve tracer when fixing
things.  I admit to have not seen everything!