After several years in storage, pressing start makes the game cycle over and over: the score reels reset to zero but the game never settles into play.

Start sequence keeps cycling after storage: clean the switch contacts and plungers

Cause: Dirty switch contacts and sticky coil plungers from storage in an unconditioned space; in this case the last fault found was around the outhole (ball drain) switches.

Checks

• Confirm the score reels reach zero; if one does not, look at its zero switch first.
• Work through the reset sequence on the schematic and check each relay and stepper switch it depends on, including the outhole parts.

Fix

• Clean all switch contacts (relays, steppers, score motor, outhole) and burnish them.
• Clean each coil plunger and sleeve, cycle it by hand, and blow out the dust.

Unplug the game before working on the relay and switch contacts: EM wiring carries line voltage at the plug, transformer and some switches.

Systems

• Electro-mechanical

Games

• El Toro

Related tips

• Score motor keeps running at start and the game never starts: clean the ball count unit
• Game keeps cycling the reset and starts in Game Over: dirty P5A switch and shorted wires
• Game won't start though credits and reels reset: bad joint on the latch coil
• Game starts but flippers are dead and nothing scores: dirty relay switches
• Player 1 'up' lights stay off during play: clean the coin unit contacts
• Game Over relay trips again right after start: dirty Lock relay switch
• Game resets but the outhole relay never fires: feed wire hanging by a strand
• Won't start a game or reset the score reels: burnt game-over relay coil

Source: Pinball Repair help group!! (Facebook group)