Williams System 6 type 2 sound trouble shooting

[Tyke]

Anyone have any tips troubleshooting a Williams type 2 sound pcb with a speech daughter pcb? I have followed most of what is online and got as far as narrowing it down to the sound pcb.

To clarify pressing the diagnostics switch on the sound board does produce the correct sounds and speech samples. Its nice and loud and the speech sounds great.

Grounding the inputs to the sound pcb does not create any sounds. I also checked them with a logic probe and you can see activity on the inputs when the correct switch is triggered. Based on this I believe the driver board solenoids are firing and sending signals to trigger the sounds.

This leaves me to a problem on the sound pcb itself... anyone got any suggestions?

 

[stevebm1]

those sound boards were used in defender and robotron too,as well as gorgar,firepower etc....,do you not know anyone local to you who's cab you can test the board in?,

 

[Jay Walker]

Hi, tyke,

Looking at the schematic, the five solenoid input lines are pulled up to 5v using resistors in package SR1, then buffered through five of the gates in IC 5 (4050 Cmos buffer chip), en route to the PIA, IC 10. They're also coupled to IC 6 (4068, 8-input NAND gate). AFAICT, IC 6 triggers the PIA input CB1, pin 18.

 

[Tyke]

@stevebm1 I do have a firepower I can test it on. Just hate messing with old cabs that are working perfectly lol

@Jay Walker thanks for that I will have a probe about and see where it fails.