Williams System 11C Sound Boards - D-11581-XXX(XX)
System-11C Sound Circuitry Tests
Tests of the System-11C Sound circuitry, including the Audio Board, are possible only after the successful completion of the System-11C Memory Chip test.
Audio Board Test. A brief check of the Audio Board (D-11581-x) circuitry occurs at game Turn-on; the game reports the test results by brief sounds as follows: No sound = Audio Board is not operating, or a failure is affecting the sound circuitry (broken cable, dead amplifier, etc.); 1 sound = system OK; 2 sounds = RAM problem; 3 sounds = U4 problem; 4 sounds - U19 problem; 5 sounds = U20.
If this test did not isolate the problem, turn the Volume Control for maximum output. Momentarily touch the center tap of the volume control with your finger - there should be a noise/hum response from the speaker.
Of course, be SURE the Audio Board has +12VDC, -12VDC, & +5VDC and Ground!
| Board photo |
Jumper List |
Notes |
D-11581-573 (Police Force)
(picture of PCB here) |
W1, W3, W5, W9 |
Parts not required: C7, C10, C11, C17, R18 - R25, R29, R30, R32, R34, U6, U7, U18 |
| D-11581-574 (Whirlwind) (picture of PCB here) |
W1, W3, W5, W9 |
27C256 Eproms |
| D-11581-50007 (Riverboat Gambler) |
W1, W2, W5, W9, W10 |
27C512 Eproms |
D-11581-2016 (Bugs Bunny)
(picture here) |
W1, W2, W5, W9, W10 |
27C512 Eproms |
| D-11581- (NBA Jam) |
W1, W3, W5, W9 |
27C256 Eproms |
|
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