87 sentra with 2bbl. I have no spark at the coil. I have signal coming from the distrbutor wires (crank angle sensor) to the cpu. I have constant power on 2 of the 4 terminals on the power transistor(one is supposed to, the other is the lead going to the tack which doesn't seem right.), There is signal coming from the cpu to the power transistor when turning the motor over. I have a constant 12v to the coil and i have a signal wire putting voltage to the coil when turning the motor over. I have the service manual on how to test the power transistor and its not testing correctly according to the book. I have went to the salvage yard and tested 5 more transistors and they all tested exactlly the same?? (are they all bad or is the book wrong?) Oh yes all of the fuses tested good. Any ideas? Please help!