I'm getting a JP together that was in storage using old broken boards. Coming up on the final stretch, but the lamp drivers are confusing me. I have no lamps, whatsoever. Bench testing reveals that if I put a bulb after the 27 ohm resistor on the drive side (other side on a return pin), it blinks happily. I get nothing at the plug, though. It seems very strange that all of the TIP 42s would be blown out at once, and I don't have any replacements at the moment. Should I have 18 volts at that resistor? I see that the data actually drives the pre-driver, and not the tip 42s themselves. So what's the problem? I have 18 volts at the other leg of the transistors, but nothing from the middle.

Edit: Now I'm even more confused. If I measure at some of the pins on cn7, I get 18v. But when I put a lamp to it and the other end to ground, it doesn't light! WTF?