Ok, I'm at the end of my road with this board..

Board came to be in an unknown state. Let's call this Board1 - It's a -61 version of the board. I also have a second, known good -61b board, Board2 that I've been using to help debug with. Boards are being tested in an Eight Ball Champ. When Board2 is in the game - everything works fine and that is the baseline.

Problem: When Board1 is in the game, I get speech only. No music, no sounds. Volume controls are fine (both coin door and trim pot) and influence output.. but only get speech.

Things proven so far:
- Board1 gets through the 5 flashes on boot every time currently
- I'm using the same ROMs in Board1 and Board2 (swapping chips) and both boards are jumpered the same for 2532 ROMs.
- Suspecting the usual suspects, I started off by doing a cap kit on Board1 including replacing the speech and sound trim pots
- Prior to replacing the caps, it had factory caps and C38 had actually leaked some. A small bit of crud on the legs of CR7 and CR8, but they still diode test fine and continuity seems intact.
- After replacing the caps, still no sounds/BG sounds
- Suspected the PIA at U11 - swapped that.. no change
- Replaced and socketed the invertor at U16 to be safe.. as that feeds the Sound Chip. No change
- Suspected the Amp/mixing path... replaced the LM3009Ns at both U13 and U14 - No change
- Remember, the input from the MPU to J1 on the board is ok, because it works fine with Board2. J1 had some nasty pins, so I replaced J1 as well.
- Q2 which works along with the low pass filter I believe I've tested as ok.

I have put all the socketed ICs except the CPU from board1 (problem board) into board2.. and Board2 works in that config. So all three ROMs (U3, U4, U5), both PIAs (U7, U11), and all three sound chips (U12, U10, and U8) and the RAM at U6... have tested good in Board2. U13, U14, and U16 are all new. Only U15 and U17 are left untouched.

I have not swapped the CPU anywhere... but given the boot sequence and its playing speech fine, I haven't suspected any problems there.

I've been toning out the paths between the Sound Chip and into U13 and U14 best I can without chasing EVERY POSSIBLE tie down, feedback, etc.. and don't see any obvious breaks. I've tested from J1 to the U16 invertor and then onto the Sound chip.. and all look fine. The main power amp is fine as its playing speech fine.. and the path from the last U14 amp to it seems fine too.

I'm stumped.

There is a TP for the output of the sound chip... but I have no idea how to test with that output. Any help there? Suggestions where to look next?

There was a little bit of flux left on J1 and u13 that I cleaned up a bit more after taking these. No bridges or anything...

IMG_3914 (resized).JPG

IMG_3916 (resized).JPG

IMG_3915 (resized).JPG

IMG_3917 (resized).JPG

IMG_3918 (resized).JPG

IMG_3920 (resized).JPG

IMG_3919 (resized).JPG

IMG_3921 (resized).JPG

I really only have backboz speakers... I assume that is too big. That's part of my problem... I can't figure out what is a legit test to work from

I have no way to test the sound on the bench... that's what I was asking about. And the game works with the other board.

I haven't done the socket, but was testing from the pin leg down to the through hole on the bottom of the board. Not sure if I've tested every leg.. but did test the lines that are fed by the MPU and the VCC and GND lines. The thing was since it was ALL sounds minus speech.. which means I'm not getting sounds from either chip.. and both are fed by different inputs.. I was hoping it was in U13 or U14 since that is where the outputs meet up.

I'll try to scavenge a small speaker and see if I can get anything out at TP7 as suggested. If not, I guess I trace everything feeding the sound chip. I know I toned out from the chip leg on the output of the sound chip down the path through all the components to the U13 input (which I think is the low pass filter first..).

The thing that wasn't too sure for me was I didn't necessarily like the readings I was getting for Q2.. but I think the circuit should still work there regardless. And wouldn't explain why I'm not getting sound from the other chip.

I'm so hung up on both chips not working. And after nuking some pins on the NLA speech chip swapping chipsets.. I need to be more careful now. I was able to solder some leads on to replace them.. but its fugly

I actually brought home a old speakerphone on friday to be a donor for a speaker I've been away so haven't gotten to test yet, but will test with the speaker and logic probe as Chris and Cody have suggested.

So... I have it working now, but I can't say I'm 100% on the solution.

I hacked out the speaker from an IP phone and tried tying it to TP7 and TP1 (GND). I got nothing when the game was playing (and should be playing background music and some effects). I tried on the speech channel, and basically could create scratching sounds out of the main output, but nothing out of my little speaker.

On my logic probe, I didn't see anything either... but in hindsight, I might not have been stimulating the game enough to see traffic there.. more on that later.

I then moved onto validating the +5, GND, CLK, and onto the data lines feeding the Sound Generator chip while the game was active to see if anything was out of line. Everything looked as intended, except I could not see any changes on the data lines that come in from the MPU->Invertor->Sound Generator. I then moved onto testing at J1, and still saw nothing (I'm expecting at least some pulsing/changes from the background effects, etc). Now remember, this game works fine with another board, with the only thing changing me me swapping the sound board itself.

So now I'm stumped, and look to test these sound select lines coming from the MPU.. Just going on wire colors it looked like J5 on the processor board looked like the output from the MPU (I can't make much sense of the processor schematic in this manual.. ugh). So I pulled J5 off, and then put it back on half-way and setup so I could use my logic probe there. In doing so, going to test again, I realize I need to do more on the game (hitting targets, etc) to get some action on the pins... then I realize... I now have sound!

So, there could be something with the J5 connector.. but I'm confused because I don't think U10 is driven by those same sound select lines. I thought the U10 chip was driven by the PIA which is driven directly by the CPU on the S&T board... so I don't know why I was getting nothing (unless no sounds I've been trying to test come from the U10??). And the other board worked fine without me touching J5 at all. So maybe just the connector was marginal.. or maybe the plugs inside the J1 connected to the S&T board (I replaced the header, but did not repin J1).

So likely J1 on S&T or J5 on the processor board maybe had marginal connections... or maybe it was a combination of that and my chip replacements on the S&T..

I hate inconclusive 'solutions' - but the game is working now. Thanks Chris, Cody, and others that responded and kept me from punting