Ive updates this post symptoms.

I’ve a strange one with my LW3
So recently some of the voices went missing, some are missing completely, some play a loud screech instead, some are fine see video in post #3.
I’ve researched but haven’t seen anyone else with similar issues
Things I’ve checked:
Ribbon from MPU to Audio board
Checked all solder joints on Audio board
Ram in Audio board
Rom in MPU
Roms in audio board
PIAs in MPU
Voltages on Audio board
I’ve recapped most the Audio board, well the caps I had handy anyway.
Reseated all connectors in back box
Checked all fuses in back box.

My DMD controller is out of the machine at the minute while I wait on a replacement so I can’t go into diagnostic but I did check prior to removing it and I’m not getting any crc errors, just missing sounds And static when cycling through on some of the sounds.

Whoops, lost video, I’ll make another and add shortly

I take back what I said above, it’s not all voices. I just noticed most them were missing but not all.
The “you have no authority” is definitely missing, just silent. “Okokok” is corrupt,
The song c&c everybody dance now is totally corrupt and plays static and loud screeching, sometimes gameplay goes totally silent.
I’ve verified the Roms in the burner

First I flipped both ends to see if the symptoms were the same. Then I swapped it out for the ribbon in my other pin

I’ve removed the sound board completely a couple of times to reflow, recap, etc. Always the same result
The voltages on the audio board though, just thinking I haven’t actually checked them while a game was in progress so I’m starting to wonder if either the 12v is being dragged down by something else or I’ve just found an interesting thread About AC ripple on the 12v

I’ve verified all roms, they are ok

Sending to the USA isn’t an option, the return shipping would cost as much as a new board or replace with a raspberry pi and I’m not sure the fault is definitely on the sound board, I’ve got a logic probe so can do some further investigation when I get time, it’s a pretty basic board logic wise so I was hoping someone here had seen a similar issue

Yep, I’m not convinced it’s anything to do with the soundboard either although that strobing is just the LEDs on video, I’m actually going to change all the inserts to standard bulbs, they look OK in person

No, just one day the sound went weird, it didn’t tie in with anything, although the LEDs are new, I’m actually going to remove them from the inserts as the strobing on videos is really annoying and I do get some ghosting despite them being non ghosting.

So now I’ve my DMD back, it’s voice ROM2, I’ve reburnt and verfied and still the same.
I’ve tested the sound board in another machine and the results are similar although would appear to be voice ROM1 in the other machine

I’ve narrowed this down to U26(TDA1543). When I do a sound test I can see activity on pin3(Data) for all sounds, even ones which don't play aloud, the working sounds I can see activity on pin8 (AOR), but the missing sounds nothing, also nothing ever comes out of pin6 (AOL). I’ve ordered 1 so will see how it goes and update the post incase it helps anyone else.