My Jokerz has music, but no speech. (Fortunately, I have a functioning Cyclone with the same CPU board)

On boot up - I get one beep indicating everything's working.

In diagnostics, it advances through music, all music tracks play. Sounds advance through from 1 to 7 with no errors, but no speech/sfx sounds play.

I hit the button on the left side of the CPU board. It's supposed to play two test sounds, one for CVSD, one for DAC. Neither play.

I swapped U15 and U24, after reading that if one was bad, it wouldn't boot. It booted and played just fine tho.

I swapped sound Roms into my Cyclone, and all the speech/sfx worked, so U21 and U22 are good.

I swapped the whole CPU board from my Cyclone into the Jokerz (Jokerz Roms swapped in), and everything works there, so I know it's a CPU board issue.

I'm looking at the manual, and it's vague enough that I can't follow. (I'm also a noob trying to learn)

1. It says to test pins 2-9 on U9 to see if they pulse on sound test. Noob question, how do i know which ones are pins 2-9? Do I test this with an electrical tester? How? connect to pins 2 and ground and see if it lights up?

2. It says to check -12 voltage. I put my meter on the -12 test spot and the ground on the board. A buzz came from the speakers, but it showed 0v. I'm sure I'm doing something wrong there. I tested the working board and it did the same thing. How, specifically, do I check for 12v?

3. It says to check if AC ripple is too high? How do I test this, and what exactly is "too high"?

4. The gray and Gray Green wires are supposed to be tested for 19.4 VAC. I don't think that's an issue since the board swap works, right?

5. It says to check the C26 capacitor for -12VDC. How exactly do you do this? Where do leads go on multimeter?

I've read up a bit on here, and I'm about ready to just shotgun approach it and replace the PIA at U9, the CVSD at U3, the amps at U4 and U5, resistor at SR1? Any idea how I can test and narrow down the issue?

Thanks for all your help!

Thanks! I am admittedly a noob trying to learn.

Looking at the schematics, there's a lot of parts that the entire circuit passes through that could be the issue. Any advice on isolating it I'd appreciate!

Someone has socketed the cvsd and the soldering doesn't look great. I'm going to dig into that, and maybe just replace the chip since it's obviously gone bad before.

One thing I'm noticing is that my 10k resistors vary wildly. Some show 6K, others 10.5K. How concerning should that be? When a resistor 'fails', what tends to happen to it's resistance?

Update! Finally got some new parts. I first replaced the cvsd, since it was socketed.

Game ran and more sounds are playing. Plays a sound on every sound test.
What's interesting is that I've swapped boards in cyclone and Jokerz. Now the cyclone is playing new sound I've never heard before. Some speech is incorrect tho. Starts at the wrong spot and ends early.

Fixed a couple other minor playful issues and started it up. Now it says u10 pia failure on the display and won't start a game.
The CPU board diagnostic led flashes 8 times. Then there blinking led flashes 10 times.
The sound board test at left now beeps 2 sounds like it should.

Should I go ahead and replace u10?

Once in a while the game boots and starts a game. When that happens, there are no flippers.
I've got 4.82 volts at test port and pin 20 of u10. Did a diode test on u10 pins 2-17 and the tested fine with the chip still on the board.
Should I replace c8? It just go for u10?