I have a Williams System 7 Laser Cue I am trying to bring back from the dead. The main issue I am trying to get through currently is I have no sound from the sound board during game play or by pushing the sound board test button. Below are the checks I have completed.
1. Voltages at sound board test points +14v, -13v and 4.86v
2. Hum at speakers after turning volume pot all the way up.
3. Reflowed solder joints for all the chip sockets, amp, and connectors.
4. Replaced several caps that were swelled. Remaining that are not swelled will be swapped once they arrive in the mail.

Before I move to checking chips, is 4.86v DC good enough for the sound board processor? Could someone check their system 7 sound board to see the voltage they are seeing? Thank you for any help or advice.

#2 2 years ago

CRD

Pinballflare

Pinside member

North Huntingdon, PA

11y 48,650 100 30 17

Bump…

#3 2 years ago

JON

Schwaggs

Gameroom Mods

10y 105K 4,760 10

4.86v is a bit low but should work.

Have you tried reseating the ROM and CPU - checking for bent legs and proper orientation?

These are single swipe sockets - I always replace the ROM and CPU sockets on this era board for better, long term reliability.

There is a 1uf and 10uf capacitor in the audio path. You should make sure that all electrolytic caps have been replaced before pulling your hair out much longer.

Is this board original to the Laser Cue? If not, make sure the proper jumpers are installed and switches set. W1 should be installed for sure and would commonly NOT be installed if this board is from another machine.

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