With voltages present and the volume turned fully up, the speaker is completely silent.
Not even static from the speaker
Cause: The TDA2002 amplifier (often cracked solder joints, because it stands up on a heat sink and gets bent), the 8 ohm speaker, or a dirty 5k volume pot with dead spots.
Checks
- Turn the volume pot back and forth with the game on and listen for changes.
- Game off: touch a 9 V battery to the speaker lugs for a second; it should thump.
Fix
- Resolder the TDA2002 on both sides of the board; replace it if +12, -12 and +5 V are present and still nothing.
- Clean the pot with contact cleaner (game off) or replace it; replace a dead speaker.
Systems
Related tips
- Check the -51/-56 PIA, RAM and amplifier with the test EPROM running
- Sound board powered but not running
- Sound CPU pin voltages with the EPROM removed
- Hum from a type 1 sound board
- Speech very faint on a type 2 board
- All sounds suddenly wrong and background gone: bad 6802 on the sound board
- Sound works for a few minutes then quits, speech still works: cracked IC solder joint
- No sound effects in play though speech works: check the sound board PIA
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Three, Clay Harrell (pinrepair.com)