The six transistors are:
1. On the roof of the Auto Shop
2. In the school basement in the room with the furnace. You may have picked this up during the "help Gary" mission going for the fire extinguisher
3. In the middle of the road on top of the dam
4. In the alley behind the mexican restaurant acros the street from the Shiny Bike Shop. You should find it by entering the alley from the North end.
5. In the basement of the Dragon's Wing Comic Book store
6. In the small alley in New Coventry where you crawl into the window to get into the tenements.