On U11 pin 15 i have no high output signal. It reads low on my logic probe and it should be high. Pin 15 feeds plug J4 pin 6 on the board. I initially installed 3 different 6821 chips and a new base but still the same. On J4 pins 5-8 are for continuous sol data. Bending up pin 15 on U11 its still low so nothing on the board is draging the signal down.
I have just found that the signal is high on start up but after around 3 secs it drops low. The above symptoms occur whether its in the m/c or on my test rig.
Could the eproms be at fault?
I have just found that the signal is high on start up but after around 3 secs it drops low. The above symptoms occur whether its in the m/c or on my test rig.
Could the eproms be at fault?
