I took some more measurements. I have another (working) MC34063 in a different circuit and took a screenshot of its timing capacitor waveform. It look exactly the same. The screenshot is attached.
I think my transistor might have become damaged during soldering. I took some new measurements and found about 8.3 V (!) at the base of the transistor relative to the emitter. It's constant too, I can't see any switching. When I use the diode test mode on my meter and measure across the base/emitter junction, I get about 0.7. When I swap the leads (red on emitter, black on base), I actually get a smaller reading, of about 0.56. When I measure across a 1k ohm resistor as a test, I get about 0.7. When I measure across the collector and base I get 0.287. When I swap the leads I get the same reading. When I measure between the collector (black lead) and emitter (red lead) I get 0.597. Swap the leads and I read 0.77.
Does this sound like a broken transistor, or are these diode readings worthless in-circuit? The 8.3V on the base should mean something.
