REPAIR LOG #2 Bally Squawk and Talk board missing sounds solved.

So I’m tasked with getting a Squawk and Talk board working for a Bally Fireball 2. I’m handed 5 boards, 4 of which are locked up and the last with no ROMS in it is marked “missing sounds.”

I burn a set Fireball 2 sound ROMS for it. I have plenty of 2732’s around, but have to change the jumpers since the board is set up for 2532’s. As far as burning goes, it doesn’t matter which chip you use, but the pin outs are slightly different and if the board doesn’t have accommodations for both then you’ll have to cut and modify a few traces. That goes beyond the scope of this article so I won’t elaborate further.

I plug the board in and have full speech but no sounds other than a blip here and there. The board has previous repairs which can make things more complicated due to the fact that there’s always a possibility that a part replaced by a previous tech is bad. I’ve had that happen several times and was the case here.

I replaced U16, (previously replaced) the 4049 inverter chip that sits between the sound select input connector and the rest of the Squawk and Talk board. Now I have some startup sounds as the game boots up but they sound off. I also have some sounds during gameplay but no background sound, (yes the option is turned on in the game adjustments).

At this point I’m pretty sure it’s an addressing problem not a RAM, ROM, PIA or other chip failure since I eliminated them by swapping in replacements. One thing to note about these Bally boards is the traces are EXTREMELY delicate and unforgiving. If you (or a previous tech) replaced chips and are still getting nowhere it’s time to start checking continuity.

I found a break between pin one on the connector, if you look closely at the photo you can see it right next to the eyelet. It goes through a 10k resistor then to the 4049. There was continuity between the resistor and the 4049 but not between the resistor and pin one.

Now I have background and all other sounds except sounds when the pop bumpers or slingshots are fired. I know it isn’t a selection problem because when they are fired the background sound is interrupted. Instead of getting a sound there’s just a second or so of silence then the background sound resumes.

This one took a little more digging because continuity on all data, address and chip selection lines are good. The problem ended up being the E signal, pin 37 on the processor was getting to the PIA, but not to the 74ls14 (U15).

Forgive me Father for I have sinned. Running jumper wires on the back of the board restored all continuity and the board is working 100%. I really don’t like running jumper wires on the backs of boards because it’s ugly and wires can get ripped off causing more headaches, but I also realize you gotta do what you gotta do sometimes.

Solder side of a Bally Squawk and Talk board.

A few things to note. Because the physical board is so delicate you need to be extremely careful when working on them. I won’t even tell you how much time I spent chasing an invisible break in continuity on these boards. Also the schematics in the manual for the Squawk and Talk is full of errors so if you’re checking continuity and things aren’t matching up it would be helpful to have another board on hand for comparison, if it’s a possibility.

Thank you for reading, if you found this article helpful, please share it.

Frank.

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