Quoted from MrSanRamon:Background sound only on sound board, speech is on MPU.
Robert
From Clay's repair guide:
3d. When thing don't work: Power-On Tones and Sound Diagnostics/Problems
"System 11 sound used 'FM sound', which is generated from the YM2151 8-voice FM synthesizer chip. Digital sound data from the YM2151 is converted into an analog signal in the YM3012 DAC chip. A preamp MC1458 chip pre-amplifies this analog signal before it is sent to the mixer and final amplifier. System11 usually assigned a pair of FM-voices for an instrument. This is what made system11 FM-synthesis stand out in sound quality and innovation. The synthesizer was also capable of making noise sounds and this was used for most of the cymbal and hi-hat sounds.
Williams used the term 'general sound' for any sound created by the MC1408 DAC chip. Sampled sounds, such as drums, are processed through the DAC. These are all 8-bit samples stored in ROM. Algorithm-based sounds are also processed through the DAC. These sounds are created by software algorithms. They are played monophonically (only one sound can play at one time), and are easily distinguished this way. Algorithm-based sound was used widely in Williams system 3 through 11B games, and it was stopped starting with system 11C games.
All speech is generated from the 55536 CVSD chip. Digital speech data is clocked serially into the CVSD chip and converted into an analog signal. A preamp chip (MC1458) pre-amplifies this analog signal before it is sent to the mixer and final amplifier." From http://www.dreamstasys.com/system11.htm.
Power-on Tone(s).
When the system 11 games boots, it produces power-on tone(s). Here is the breakdown of the tone(s):
• No Sound: sound/speech board is not operating, or a failure is affecting the sound circuitry (broken or disconnected cable, dead amplifier, bad speaker).
• One Tone: sound/speech system OK.
• Two Tones: sound/speech RAM problem.
• Three Tones: U4 problem.
• Four Tones: U19 problem.
CPU Sound Diagnostic Switch SW1.
Testing the sound circuitry is only possible after successful completion of the system 11 power-on CPU tests (as described above). That is, the game must boot properely and go into "attract" mode, with no power-on beep tones.
On the left side of the CPU board there are two switches. The top switch SW1 is the sound diagnostic switch. If you press this button, you should get two test sounds. This shows that the CVSD (Continuously Variable Slope Delta) modulator, which produces the game's voices, and the DAC (Digital to Analog Converter) sound circuits are working.
After pressing CPU switch SW1 you should get some tones. Here is the breakdown:
• No Sound: sound/speech board is not operating, or a failure is affecting the sound circuitry (broken or disconnected cable, dead amplifier, bad speaker).
• One Tone: U23 RAM chip error.
• Two Tones: U21 ROM chip error.
• Three Tones: U22 ROM chip error.
• Four Tones: U21 ROM chip error.
• Five Tones: U22 ROM chip error.
No Sound when CPU switch SW1 is Pressed (but sound heard during diagnostic tests).
Check the sound select inputs (U9 pins 2-9) with a logic probe to see if they pulse during Sound Test 01. Also check the -12 volt supply voltage on the CPU board. If this voltage is low (or AC ripple seems high), perform the following checks (you can check for ripple using your meter set to AC volts; more than .75 AC volts is probably too much AC ripple).
• Check the gray and gray/green transformer secondary wires for 19.4 volts AC.
• Check the CPU board filter capacitor C26 for -12 volts DC.
• Check the CPU board filter capacitor C26 for AC ripple (over .75 volts AC).
If the above tests did not find the problem, turn the volume control up all the way, and momentarily touch a powered-on AC soldering pencil on the center tap of the volume control (do NOT use a solder iron over 40 watts, and a cordless soldering will not work for this test). If you hear a low hum, this means the power amplifier (U1, TDA2002), the volume control, the speakers, and the sound cabling are all working.
If you don't hear the hum in the above test, turn the volume control down slightly, and repeat the soldering iron test.
This should isolate if the volume control is at fault.
Also check the cable connectors for proper mating, and that no wires are broken.
System 11 Sound Board Generations.
All system 11 games used sound board D-11581 except High Speed, Grand Lizard, Pinbot, Road Kings, Space Station, and Jokerz:
• High Speed (sys11): Background music board D-11297.
• Grand Lizard (sys11): Background music board D-11297.
• Road Kings (sys11): Sound board D-11298 (first game to use a Yamaha YM2151 sound chip on the sound board).
• Pinbot (sys11a): Sound board D-11298.
• Space Station (sys11b): Sound board D-11298.
• Jokerz (sys11b): Used a special stereo sound board D-12338 with different sound board power requirements and cabling. Also CPU board jumpers W1,W2,W4,W5,W7,W8,W11,W14,W16,W17,W19 must be installed.
The commonly used system11 D-11581 sound board utilized a 68B09E CPU, YM2151/YM3012 8-voice FM sound synthesizer (8-bit sound), a MC1408 DAC (Digital/Analog Converter), and a 55536 CVSD speech chip. The U4 EPROM contains the sound board operating system and YM2151 music data. EPROMs U21 and U22 contain speech and/or 8-bit sample data. If looking for this sound board, it can usually be bought cheaply because it was also used in some late 1980s Williams video games (Arch Rivals, Trog, Smash TV, High Impact, and Strike Force).
High Speed and Grand Lizard used background music board D-11297. It used a 68B09E CPU, a single MC1408 DAC for processing 8-bit digital samples stored in EPROM. On this board the U4 EPROM chip contains the operating system and 8-bit digital sample data. The operating system on this chip is compatible with the D-11581 sound board.
Saint Paul, MN
Thanks Jeff, I had never hear of that place before.
