I have two rows of lights out on my Hyperball and saw that they are linked to Q19 and Q25. However, after looking in the manual it just says that they are NPN darlington transistors, it does not tell the specific kind of transistor. Does anyone know the specific kind?

Are the TIP 101 and TIP 121 interchangeable? I am safe to ground out the metal tap on the two affected row transistors and see if the rows turn on correct? If they turn on then at least I know that the wiring going from the board to the play field is good.

I tested Q19 and Q25 on diode test. Also tested IC1 and IC2. Tested good

Would grounding the tab on Q19 and Q25 hurt anything? I read somewhere that you dare not ground the tab on column transistors but its fine to ground on row transistors.

I have a logic probe, I down know how to use it.