(Topic ID: 254969)

High Speed Sound Completely Gone


By Andy_B

17 days ago



Topic Stats

  • 20 posts
  • 7 Pinsiders participating
  • Latest reply 2 days ago by gutz
  • Topic is favorited by 1 Pinsider

You

Linked Games

Topic Gallery

There have been 5 images uploaded to this topic. (View topic image gallery).

HighSpeedSound (resized).jpg
pasted_image (resized).png
20191113_195009 (resized).jpg
20191113_194959 (resized).jpg
hss (resized).PNG

#1 17 days ago

I had a problem with missing speech on my High Speed which re-appeared after I had pressed on some of the chips in the sound section of the CPU. All sounds were working correctly before this.

The sounds then all worked fine for a couple of games before I noticed an unrelated issue of the kickback not working - diagnosed to a faulty Q7. I took the CPU board out to replace Q7 and also the pre-driver Q5, and then the correct pre-driver Q3 due to the schematics being wrong

After re-fitting the CPU board I have no sounds at all. At one point I could hear the music play very faintly through the speaker with the volume turned up fully in Music Test but this has now also disappeared.

I have checked previous post on similar problems but it makes for quite vague reading.

Could someone point me in the right direction with what I should be checking first?

Thanks

Andy

#2 17 days ago
Quoted from Andy_B:

After re-fitting the CPU board I have no sounds at all.

Can you test for negative 12 volts at U-2 pin 3. You may have a cracked header pin on 1J-17 or 3J-6.

#3 14 days ago

FInally got some time to have a look at this.

Got 15.25v at U2 pin 3 and the same at R9 which feeds to U2 pin 4.

I understand that the sounds are produced on the sound board and also the CPU but I'm struggling to understand where the bottleneck is likely to be whereby whatever component(s) has failed would kill all the sound.

#4 14 days ago

Sounds are stored ans processed in the yellow box area. When the game calls for a sound, it is selected from the green box area. Voice clips are at the top yellow arrow and digital processed sounds are on the lower yellow arrow. The voices are amplified thru 2 op amps, sound are amplified thru Q-1. Both sets of sounds come together at the very left and go thru another op amp as combined sounds and leave the board to go to the background sound board and volume pot. Then the sounds come back in from the volume pot red arrows and to the main amplifier and leave to go to the speakers.

hss (resized).PNG
#5 14 days ago

Since you have no sounds at all now you need to go to components that affect both speech and sounds and background sounds. This is why I had you check the -12 volts as this powers the amplifiers. Other things to look at would be the volume pot, C-2, C-3, U-1 on the CPU board. Also check for the -12 volts on the background sound board on on side of C-6.

#6 14 days ago

Thanks for that its really helpful. With the lack of speech and a few other sounds before total failure I am not suspecting speakers (which are both new in any case) or volume pot but I'll test them and work back through the schematic.

Is an oscilloscope required for full analysis of the sound circuitry?

When I press the sound test button on the CPU board I can here faint crackling through the speaker on max volume but nothing recognisable as the sounds the game makes.

#7 14 days ago
Quoted from Andy_B:

Is an oscilloscope required for full analysis of the sound circuitry?

It is very helpful. Since you pulled the CPU board, you removed 1J-17 connector. The Sound board is also tied to 1J-17. You may have pulled a wire from the sound board power connector causing all the sounds to stop.

#8 14 days ago

Probably a typo, but in post 3, Andy_B got 15.25v at U2 pin 3, not -12v.

#9 14 days ago

Yeah I saw that but thought he just left out the minus sign.

#10 14 days ago

There is a cable that connects the background sound board to the CPU board, disconnect it from the CPU board. Then disconnect the other cable from the background sound board that goes to the volume pot and connect it to the CPU board where you just disconnected the other cable. Play a game to see if game sounds work. There won't any background sounds tho. But this will tell you which board is acting up.

#11 13 days ago
Quoted from GRUMPY:

There is a cable that connects the background sound board to the CPU board, disconnect it from the CPU board. Then disconnect the other cable from the background sound board that goes to the volume pot and connect it to the CPU board where you just disconnected the other cable. Play a game to see if game sounds work. There won't any background sounds tho. But this will tell you which board is acting up.

Ok I'll give that a whiz.

It was a typo in the previous post. Voltage was -15.25v

#12 12 days ago
Quoted from GRUMPY:

There is a cable that connects the background sound board to the CPU board, disconnect it from the CPU board. Then disconnect the other cable from the background sound board that goes to the volume pot and connect it to the CPU board where you just disconnected the other cable. Play a game to see if game sounds work. There won't any background sounds tho. But this will tell you which board is acting up.

Ok. Done that and still no sound. Just getting crackling from the speaker when sounds are played.

Is there a quick and easy way to test the amllifier chips?

#13 12 days ago

Can you post a picture of the MPU and the sound board?

#14 11 days ago
Quoted from Andy_B:

Is there a quick and easy way to test the amllifier chips?

You are going to need a Oscope for this type of testing.

#15 9 days ago

Pics as requested. Let me know if you need anything closer.

I have no knowledge of using an oscilloscope although its a good time to learn

Will this be suitable?

https://www.ebay.co.uk/itm/Hantek-2-Channel-Digital-Oscilloscope-6022BE-Used-only-once-near-mint/293319587585?epid=28032583594&hash=item444b35b701:g:8zgAAOSwCOJdvzIf

20191113_194959 (resized).jpg20191113_195009 (resized).jpg
#16 9 days ago
Quoted from Andy_B:

Will this be suitable?

I really can't say as I have never used a PC type Oscope. I just have a 25 year old 2 channel Tektronix.

pasted_image (resized).png
#17 4 days ago

I see your problem, you somehow mis-wired the cables when reinstalling your CPU board.

The sound board should have both of the left-hand 4-pin connectors populated, you only have the top one (J1) filled, the bottom one (J2) is empty. There should be a short cable leading from J1 on the sound board to J16 on the CPU board (top row, second in from the left).

If you look closely at your bottom picture, you can see a 4-pin connector sandwiched in the middle of a bunch of wires that's not connected to anything. My guess is this is the cable coming from J1 on the sound board.

The cable presently connected to J16 on the CPU board goes to J2 on the sound board, it should be a very long cable that goes down to the volume knob.

For reference, I have included a picture from my game.

HighSpeedSound (resized).jpg
#18 2 days ago
Quoted from ufopinball:

I see your problem, you somehow mis-wired the cables when reinstalling your CPU board.
The sound board should have both of the left-hand 4-pin connectors populated, you only have the top one (J1) filled, the bottom one (J2) is empty. There should be a short cable leading from J1 on the sound board to J16 on the CPU board (top row, second in from the left).
If you look closely at your bottom picture, you can see a 4-pin connector sandwiched in the middle of a bunch of wires that's not connected to anything. My guess is this is the cable coming from J1 on the sound board.
The cable presently connected to J16 on the CPU board goes to J2 on the sound board, it should be a very long cable that goes down to the volume knob.
For reference, I have included a picture from my game.[quoted image]

Good Eye. That would definitely cause no sound. It goes to the speaker volume potentiometer.

#19 2 days ago

This is why I like seeing pictures of boards/wiring. Cannot always tell by symptoms if something is connected/disconnected, inserted wrong, etc...

#20 2 days ago
Quoted from GRUMPY:

There is a cable that connects the background sound board to the CPU board, disconnect it from the CPU board. Then disconnect the other cable from the background sound board that goes to the volume pot and connect it to the CPU board where you just disconnected the other cable. Play a game to see if game sounds work. There won't any background sounds tho. But this will tell you which board is acting up.

I think the picture was taken after Grumpy had him do some testing to isolate the problem to either the mpu or the sound board in post #10.

Promoted items from the Pinside Marketplace
$ 14.00
Electronics
Yorktown Parts and Equip
$ 10.00
Cabinet - Sound/Speakers
Gweem's Mods
2,300
Machine - For Sale
Cincinnati, OH
$ 29.99
Eproms
Matt's Basement Arcade
$ 19.99
Eproms
Matt's Basement Arcade
$ 164.99
Lighting - Led
PinballBulbs
$ 109.00
Cabinet Parts
Tilted Pinball
4,000
Machine - For Sale
Toms River, NJ
From: $ 18.00
Apparel - Men
Pinside Shop

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside