I have a williams swords of fury with no music. All of the callouts appear to work but no music. I get a bong at startup but I do hear some during gameplay. I've verified and replaced several roms.
Does the music come from the sound board? I don't get interruption when the bong sounds. does the amp section work independent of the controlled part of the sound board.

What should I be looking at here?

Thanks

Reseated everything. Brought back a few segments on the display but music still out
I checked the red stripe on both ribbons and reseated. Also reseated audio and power connectors on the sound board

Here's some pics. I'll add that I burned new roms on the sound board and the roms on the mpu have been verified against the current set on ipdb

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Speech/Sounds works fine. No Music at all during gameplay or test. Music has never worked as long as I have had the game (couple months)

Update: I tested the 6116 ram on the sound board. Tested fine. Music still out

It bongs once on startup. Pressing the test button plays 2 sounds (not bongs)

uncivil_engineer gave me these Troubleshooting D-11581 Williams System 11 Sound tips on FB and I wanted to share them so they're searchable

Ok here are the basics of how late System 11 audio boards work.
There are two sound system in the machine, one on the main MPU and the other on the sound board. The MPU sound section is more or less used for sound effects. The sound it produces is output via 1J16 to 10J1 on the sound board. All the sound mixing and amplification takes place on the sound board.
The sound board itself is a small independent computer that mostly does music (and in some cases voices) for system 11 machines. When the sound board is reset, you will hear the distinctive Williams 'bong' sound that indicates it has passed it's self test and has booted up. If you hear no bong, or more than one bong, you have an issue with either the rest signal reaching the board, or if you hear multiple bongs, it means there are RAM or ROM problems. The music test in the diagnostic modes will test just the sound created on the sound board.
When working on these sound boards, its best to think of them as having a digital side, and an analog side. The digital side has your typical video game sound generating logic, using a YM3015 and a Yamaha YM2151 to create sounds, and then it put the signal to the analog side of the board where it is mixed with the signal from the MPU and then output to 10J5.
The sound board communicates with the MPU board through 10J4 and the 6121 at U12. The signals (PA0-PA7, CB1 and CB2) are held high until there is a call from the MPU, and then they go low. There are a couple of videos on youtube of people who have rigged up bench drivers for these boards.
The most common problems I have seen with these board are with the ribbon cables. Try reversing the cable and see if the board works. I've also seen the YM2151 fail. Having an oscilloscope is very handy when working in the analog sections of these board as you can trace the signal as it comes out of the YM chips to the amps.

And as uncivil_engineer stated...the problem with my music was a bad ribbon cable!