(Topic ID: 297299)

Solved: Gottlieb System 80 Sound & Speech - intermittent groan on power up

By sparky672

89 days ago


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  • 176 posts
  • 14 Pinsiders participating
  • Latest reply 27 days ago by sparky672
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There are 176 posts in this topic. You are on page 4 of 4.
#151 37 days ago

I hope the videos with the horrific noise stay in this thread for posterity. I can come back here and play them with my headphones on whenever something is really annoying me and I won't feel so bad.

#152 37 days ago
Quoted from Robotworkshop:

Just to add that my Volcano also does the odd groan on power down. I don’t believe there is any issue with that but I have never heard it on power up.

FWIW, mine groaned, hissed, bweeeeeeeed, whooshed, and burped on shut-down occasionally, right up until I replaced U10.

I must have cycled power a hundred times over the last couple of days and not one tone on power-up or shut-down since the last part was replaced. In my opinion, this demonstrates that these errant tones on power cycling are not part of proper operation as designed.

I believe both the power-up and shut-down groans are both caused by tired chips and spikes. Just tired, not defective, as the sound & speech board worked perfectly fine during normal game operation. Prime example: U25 when replaced with a couple good-testing NOS 7404 chips, A6 board would not boot at all (no sound/speech) about half the time, and when it did boot, it was perfectly fine during normal game operation. The age/condition of these particular chips seem to be most critical and apparent during power cycling, not game play.

#153 37 days ago
Quoted from frenchmarky:

I hope the videos with the horrific noise stay in this thread for posterity. I can come back here and play them with my headphones on whenever something is really annoying me and I won't feel so bad.

I plan on leaving them up.

#154 36 days ago

Still holding good!

Attract mode set to 10 seconds. Video shows me turning it on/off several times without any weird sounds on power-up or shut-down. I even shut it down a couple times during sound play. (I have my doors/windows open so you can hear the wind/trees and traffic noise in the background... there is no hiss, just windy outside.)

Given the history, I am still going to wait a few more days before declaring victory.

#155 36 days ago

The attract timing settings on these boards in home use is like the Three Little Bears, every 4 min is a little too long, 10 seconds is way too short and 2 min is just right. 10 seconds quickly drove me insane.

#156 36 days ago
Quoted from frenchmarky:

The attract timing settings on these boards in home use is like the Three Little Bears, every 4 min is a little too long, 10 seconds is way too short and 2 min is just right. 10 seconds quickly drove me insane.

Totally agree.

I normally have mine at 2 minutes, but found that 10 secs is great for testing, as the sound starts 10 secs after power-up, which is 5 seconds after the MPU boots.

#157 36 days ago
Quoted from frenchmarky:

The attract timing settings on these boards in home use is like the Three Little Bears, every 4 min is a little too long, 10 seconds is way too short and 2 min is just right. 10 seconds quickly drove me insane.

Former has my Black Hole set to 10 seconds, maddening. Have not had the few minutes free to pull pin out and set to something more reasonable.

#158 35 days ago

I had it 10 seconds. It stayed that way because I did not want to move the game out to get into the head.
The other day the 5101 puked.
I was in there and changed it to 4 minutes. Tested it before removing the MPU.
It was driving me crazy at 10 seconds.

#159 34 days ago

One good thing about 10-sec attract mode is that you'll never walk away accidentally leaving machine turned on.

#160 34 days ago

Well I be reviewing this thread as my BH has decided to make some rude vocalization glitches along with the power off groan. Did caps on sound board, zero change.

#161 33 days ago
Quoted from gdonovan:

... Did caps on sound board, zero change.

No surprise there. Caps are cheap and it never hurts to replace them, but capacitors are not a magic bullet. Sometimes focusing on them too much sidesteps real issues and more serious troubleshooting.

When does the issue happen for you?

#162 33 days ago
Quoted from sparky672:

No surprise there. Caps are cheap and it never hurts to replace them, but capacitors are not a magic bullet. Sometimes focusing on them too much sidesteps real issues and more serious troubleshooting.
When does the issue happen for you?

Anytime speech is present. Sometimes normal, other times very glitchy sounding.

#163 33 days ago
Quoted from gdonovan:

Anytime speech is present. Sometimes normal, other times very glitchy sounding.

Put a logic probe on pin 7 of SC-01 while speech is happening. Signal should stay low and each phoneme will be seen as a brief pulse. For my issue, I could see extra pulses when I clicked the power switch. Maybe you will see your audio glitches as extra pulses?

#164 33 days ago
Quoted from sparky672:

Put a logic probe on pin 7 of SC-01 while speech is happening. Signal should stay low and each phoneme will be seen as a brief pulse. For my issue, I could see extra pulses when I clicked the power switch. Maybe you will see your audio glitches as extra pulses?

I did a quick check this morning: Speech is always happening but glitchy/stuttering or very fast, never slow. Tried adjusting the pitch to "clean the contacts" but had no meaningful change in regards to the problem.

#165 33 days ago
Quoted from gdonovan:

I did a quick check this morning: Speech is always happening but glitchy/stuttering or very fast, never slow. Tried adjusting the pitch to "clean the contacts" but had no meaningful change in regards to the problem.

If the pitch is fast, maybe the frequency pot on the speech circuit has completely failed or flaking out? Pull the board and measure resistance while turning the pot.

#166 33 days ago
Quoted from sparky672:

If the pitch is fast, maybe the frequency pot on the speech circuit has completely failed or flaking out? Pull the board and measure resistance while turning the pot.

I'll check, but running adjustment back and forth changed nothing.

#167 33 days ago
Quoted from gdonovan:

I'll check, but running adjustment back and forth changed nothing.

The pot number depends on the version of the A6 board. If it's v3 like mine, then for adjusting speech frequency, it would be pot R6 (10 kΩ). If turning R6 has no effect on pitch or speed of speech, then this pot would likely be bad.

#168 33 days ago

Be a few days, tied up on a few projects already.

#169 31 days ago

My BH's speech vol pot didn't just fail - I broke it open and the resistive trace had *completely* dissolved away except for the ends. The freq pot likely wouldn't fail that catastrophically since it doesn't have nearly that much juice going thru it, but of course it could still fail or be dirty or have a bad solder joint.

#170 31 days ago
Quoted from frenchmarky:

My BH's speech vol pot didn't just fail - I broke it open and the resistive trace had *completely* dissolved away except for the ends. The freq pot likely wouldn't fail that catastrophically since it doesn't have nearly that much juice going thru it, but of course it could still fail or be dirty or have a bad solder joint.

I'm going to make a video and upload to youtube, just busy on a lot of other things and little time to to devote to BH right now.

The problem will also change minute to minute without even touching the machine. One second it will sound almost normal, the next gibberish. I'm thinking it's in the SC-01 circuit as the regular sound effects are fine so that does narrow it down a bit.

#171 31 days ago

There is voodoo in that SC-01 !!

#172 31 days ago

And that pot may be a multiple-turns type, like 10 turns each way, something to consider when doing the turning-it-back-and-forth-to-clean-it thing.

#173 31 days ago

The speech frequency pot could be verified and ruled in/out pretty easily with a DMM.

Put one lead on the middle leg and the other lead on one of the two ends. Watch the resistance value as the screw is being turned. Is it moving slowly and predictably (good), erratically, or not changing at all. It should be the former. With the screw turned all the way in one direction it's going to read zero, and all the way in the opposite direction it's going to read 10 kΩ. Make note of an initial reading so you can get it back to where you started.

#174 28 days ago

Pot readings are fine and currently both are set at 5k for lack of better options.

R9 tests at 2.2 which is factory correct.

While board was out, cleaned legs on all socketed chips, no change. I'd upload a video but YouTube being difficult this morning.

When you first fire up, sounds like Alvin and the Chipmunks, after a few cycles it starts to change like a component is warming up.

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#175 27 days ago

4 videos stitched together.

#176 27 days ago

Since that definitely sounds like an issue with pitch (frequency), it greatly narrows it down to the clock circuit.

Assuming you have version 3 of the board...

A6 v3

You've already tested the pot. That leaves a few resistors, capacitors, an LM741, and a couple transistors.

But before changing any components, I'd verify that the +12 VDC and -12 VDC input voltages are stable and correct at all times.

There are 176 posts in this topic. You are on page 4 of 4.

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