Posts tagged: 74LS157

Tempest repair log – auto firing logic issue

Status: FIXED

Repair cost:  $0.50

KLOV Posthttp://forums.arcade-museum.com/showthread.php?t=156908

Symptom:  Single shot firing doesn’t work.  Holding fire button down for auto-fire does work.

Diagnosis:  Since firing works, button is working.  Logic issue.

Fix:

  • 10/30/2010 – Traced fire button back to 74LS157 @ D6 (Aux board).  Replaced chip and single shot firing now works.