I'm working on a Rock right now with no sound. Press the red button on the sound board. If you hear something from those, then your set up (speakers, amp, etc.) is good. Somehow my amp connector was corroded so I had to hard wire I the amp up and was able to get test sounds from there. Next step would be to do this series of tests:

Testing the Data Pathway, Easy Method.

After the sound/speech board itself is tested (as described above), it's best to test the pathway from the CPU board to the Driver board to the Sound/Speech board. This will test the chips and connectors in this pathway. There is no sense changing chips if the connectors are at issue, or vice versa. And this test will identify these problems in a very easy manner.

Step 1: Test the Sound/Speech board. This is described above. If the sound/speech board is missing any sounds S1 to S16, stop now. Fix or replace the sound/speech board.

Step 2: At the driver board find chip Z13. Game on and in attract mode. Using an aligator test lead with one end connected to ground, touch the other end of the lead to Driver board chip Z13 pin 2 (s1), pin 4 (s2), pin 6 (s4), pin 7 (s8). A game sound should be heard for each sound S1 to S8. These are the output pins of Z13, so this tests the connection from the driver board to the sound/speech board. If any sound is missing, check the driver board A3J5 connector (upper left) pin 6 (s1), pin 5 (s2), pin 1 (s4), pin 7 (s8). If OK examine the sound board connector A6J1 pin 8 (s1), pin 9 (s2), pin 11 (s4), pin 12 (s8).

Step 3: At the driver board find chip Z13. Game on and in attract mode. Using an aligator test lead with one end connected to +5 volts (I use the POSITIVE lead of CPU board capacitor C1 next to connector A1J1), touch the other end of the lead to Driver board chip Z13 pin 1 (s1), pin 3 (s2), pin 5 (s4), pin 9 (s8). A game sound should be heard for each sound S1 to S8. These are the input pins of Z13, so this tests the chip Z13 on the driver board.

Step 4: (Does not work for Black Hole.) At the driver board find chip Z3. Game on and in attract mode. Using an alligator test lead with one end connected to ground, touch the other end of the lead to Driver board chip Z3 pin 7 (s16). A game sound should be heard for sound S16. This is the output pin of Z3, so this tests transistor Q10 (MPS-A13) and the connection from the driver board to the sound/speech board. If this sound is missing, replace Q10 and check the driver board A3J2 pin 9 connector (lower right). If OK examine the sound board connector A6J1 pin 2 (s16).

Step 5: At the CPU board find chip Z31. Game on and in attract mode. Using an aligator test lead with one end connected to +5 volts (I use the POSITIVE lead of CPU board capacitor C1 next to connector A1J1), touch the other end of the lead to CPU board chip Z31 pin 6 (s1), pin 3 (s2), pin 11 (s4), pin 8 (s8). A game sound should be heard for each sound S1 to S8. These are the output pins of Z31, so this tests the connection from the CPU board to the driver board. If any sound is missing, check the A1J4 to A3J1 connector.

Step 6: At the CPU board find chip Z31. Game on and in attract mode. Using an aligator test lead with one end connected to +5 volts (I use the POSITIVE lead of CPU board capacitor C1 next to connector A1J1), touch the other end of the lead to CPU board chip Z31 pins 4&5 (s1), pins 1&2 (s2), pins 12&13 (s4), pins 9&10 (s8). A game sound should be heard for each sound S1 to S8. These are the input pins of Z31, so this tests the chip Z31. Note you are touching the aligator test lead to *two* pins of the Z31 chip at the same time. This is an ADD chip, so for the output to trigger both chip legs must go high at the same time.

On my machine, I got very little response from these tests and tried replacing z31 and z13. Next step, I guess would be to repin the connectors. I found that I'm getting the "check sum error 7B3D" after the memory test in test mode so I'm going to try a new game ROM first (I mean, why not take the illogical path only to find out it was simply the connectors )