Hello all.
I need some guidance on a sound issue with a Data East Time Machine. I can fix a lot of things with pins, but struggle when it comes to sound.

Backstory: We picked this dirty toilet up at an auction for 950. Good cosmetically, ramps are all in tact. I got it playable in a few hours but a sound issue still persists.

Background music (ROM3) is loud and crisp. Sounds can be heard from all 3 speakers.
Voices (ROM1 & ROM2) produce a loud static noise. No sign of speech whatsoever.

From research I've done, it seems the sound board has a section the produces the speech. I'm not sure what direction to go here. Speech processor going bad?
The same results are produced during test mode as well.

Thanks

I have been reading some posts on Google help boards. That MSM5205 seems to pop up a lot as problematic. I sourced a few and I'll go from there. Thanks for the reply.

I'll check some voltages on the board. I believe the issue is isolated to the voice section. Background sound and other non-speech sounds play fine.
I get a burst of static when voices are to be played. It seems possible that the voices are triggered correctly, but not interpreted correctly. Could be a cap issue I suppose.
Thanks for your reply.

I checked all the voltages on the board. They are all present and strong.

I'm looking at the schematics on my phone. (Very hard to see) and I'm seeing a couple caps near the 5205 but they seem not have a value listed.
Hawk007 if you can give me some specific components to check, it would be much appreciated. I struggle badly with sound circuits. Again many thanks for your assistance.

I dont hear distorted voices...its varying degrees of static. When the game first boots it's supposed to say "Time Machine". I get a string of static, then it quits. Attract music kicks in next and plays normally.
It does make me think a cap has dried out.
Thanks for suggesting c29, that verifies my first pick. I'll try to source a few of those. They are easy enough to change out. I'm pretty decent with board work.

I thought this too. I have access to another Time Machine. I can verify the ROMs in the other working game. I can check those tomorrow.

Thank you for the guidance. I will follow your suggestions and report back once i have replacement parts in hand. I am determined to get this thing functioning correctly!

Swapped out c29 today, no change. I'll wait for the 3403 ic op amps to arrive and swap that next.

Replaced the 3403 this evening. No change. Still static pops when voices are supposed to play. Maybe it is the 5205 voice synthesizer

Update: received and changed the 5205 chip. The static is gone. But I have a loud "beeeeeeep" in place of any voice. Sound test results in the "beep" for both voice roms. Sound effects are still working fine.

I have not been able to verify the ROMs. My friend hasn't been around to check them in his machine. Seems unlikely both voice ROMs are bad yet the 3rd sound effect is ok.

Still stumped.

These are the new chips. Possible they are incorrect? I saw a couple different M5205 chips around.

I was buzzing each ponb of the socket a d pretty sure they all connect to the next component in line. I will def double check.

Headphone probe sounds cool...will google that!

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To update this, I sent the board to Clive at Coin Op Cauldron. His profession opinion is that its a data addressing issue somewhere on the board. But at that same time he will recap and address any other issues. I'll update this again once the final verdict comes in.

Yes, there was a short under the 5205 oki chip socket. Bad rework from somebody tinkering. That was the main problem along with bad caps. Also upon return, a voice ROM was still not working. This turned out to be the ground leg broken loose from the ROM chip from testing and replacement at the shop. Clive sent a brand new ROM at no charge.