Black Knight 2000 Jet bumpers not working
The jet bumpers were not working on the Black Knight 2000. The first thing I did was test the fuses on the auxiliary power driver pcb, at least so I thought. Everything tested fine so I looked at the fuse under the upper playfield, it too was fine with the exception of it being the wrong amperage, I changed it to the correct value. I looked for disconnected wires and did not see any. The next day I checked the fuses again and they were fine. So I started to meter voltage, from the jet bumpers back, until I found my issue. I checked voltage at the connectors of the interconnect pcb under the playfied, the back box interconnect and finally the auxiliary power driver pcb. I did not have voltage anywhere. Following the schematics all the way back to where I did not have voltage on one side of the fuse at F3. I thought I had tested this fuse as well as F1 but now question whether I missed those two or not. I removed the fuse and tested out of circuit and although it looked good, it was bad. Replacing the fuse brought the jet bumpers back. I metered the Jet bumper coils prior to powering back on to make sure they were not the reason the fuse went bad, they tested fine at about 3.5 ohms each. Fuse F3 is the one right under the relay and F1 is below that.