Quoted from frunch:

Shorting that transistor tests the path from the transistor to the coil, but doesn't actually test the transistor itself.
Looking at the chart at the beginning of the manual, it says Q22 is the driver transistor for the knocker (when the A/C relay is off, which activates the A side) and the flasher (when the A/C relay is active, which activates the C side). It's important to note there's also a smaller 2N4401 pre-driver transistor at Q18 activates the TIP122 at Q22. I always make it a point to replace both the driver and pre-driver transistors at the same time, even though it may not always be necessary. You can also substitute the TIP122 transistor with a TIP102 (slightly beefier version that's commonly used for repairs) if you replace Q22. How did you check the transistors?

Quoted from frunch:

Do you have a logic probe? The 7408 should be easy to check with one.
It's also possible you have a bad transistor that still reads good with your meter. Not likely, but i still wouldn't rule out the transistors completely yet.

Quoted from frunch:

You'll need to hook up your logic probe to the +5v and ground points, set it for TTL, and then you'll probe pins 4, 5, and 6 of U19.
U19 is a 7408 which is an AND chip, meaning that for every pair of inputs and one output, both inputs must be high to make the output go high. The chip has four pairs of inputs with an output for each pair. If you look at the chip schematic below, you can see the inputs and outputs on the left and the table on the right telling you what your probe should read at the output given the inputs. [quoted image]
I gotta admit, this is getting close to the boundary of my expertise. What i would try next would be to put the game in the coil test and set it to repeatedly fire the problem coil. While it's set up to do that, read the inputs (pins 4 and 5) and the output (pin 6). I would think you should be getting a high signal on one of the inputs and a high pulse on the other during the coil test. You should also see a high pulse at the output. Again, this info is to the best of my knowledge--so if anyone following along wants to jump in and steer us further along please don't hesitate!