There is no background music on my Williams Big Guns, and there is a full column of lights out.
For the column of lights, I would think I should just replace the proper transistor for that column, in this case Q52 in column 8, as indicated on the lamp matrix. Is this correct? Of course, this is after verifying continuity in the wiring and that the connectors are solid with no cold solder joints, ect.
For the sound issue, at power on, you hear one bong, and it boots into attract mode and is fully playable. According to the manual, one bong at power up means the audio board circuitry is good.
Pressing the sound test switch (SW1) on the main CPU produced the 2 proper test sounds, which indicate that the CVSD and DAC sound circuits are functioning properly. This *should* also indicate that U21, U22, and U23 are good.
In diagnostic testing mode, during the SOUND test, all sounds are heard properly from 00-07.
In diagnostic testing mode, during the MUSIC test, NO sounds are heard from 01-06.
What could be the issue here?
UPDATE: I just went through and reseated all the chips in sockets on the MPU, since I already did this on the audio board earlier with no change. When I remove a chip, I also clean up all of the legs on each chip before I reinstall them, making sure to power the game on again and check for any changes after each chip.
I have already checked all boards for cold solder joints and cleaned all connector pins.
In this case, I got through all of the chips with no change, until I removed chip U25 (the last one to do in my case) and cleaned it's legs. This chip was filthy for some reason, WAY more than any other chip. When I reinstalled, I got 5 beeps at power up, which I had not gotten before. You still hear the single "bong" indicating that the audio board circuitry is OK, as well as hearing 5 separate tones. According to the manual, this is an indication that U22 is bad. I removed U22 and replaced the socket, since it looks to be one of the horrid Scanbe type that only contacts one side of the chip leg. Installed the new socket and put the chip back. I still get the 5 tones, so I ordered up a set of sound/speech ROM chips.
I'm going to guess that something that routes through U25 has to do with sound/speech and wasn't actually making the proper connections so that the bad U22 indication wasn't sounding at boot up.
I'll update when I get my new sound/speech chip set and install it.
As for all of the lights in column 8 being out, am I correct in assuming I should just replace Q52 (TIP42) and all should be well?