Sounds like you might to take a break from it for a few days Beaky.
Na not just yet. I will give it another go tonight.
At times like these i really wish I had an oscilloscope.
I am getting a signal up to the 74hctxxx when the switches are activated and I know that the when i pull the data lines low with the 74hctxxx chips out the program I am running on the pc I have connected to the parallel port on the driver board shows that the data lines are going low. I know that the 74hctxxx chips are fine for the switch matrix.
So next thing I will check are the I.C.s for the register control.
Then If that is not the problem then I will be checking the I.C.s on the data bus that control the lamp and solenoids.
I know that sounds strange but if the I.C,s that are related to monitoring the fuses can cause a problem with the door switch and the start button then anything is possible on this board.
