An electro-mechanical game that ran before it was taken apart misbehaves once reassembled.

EM game worked before the move but not after

Cause: Dirty or corroded pins on the head and playfield plugs.

Checks

• Unplug each connector and look at the male pins for dull or green corrosion.

Fix

• Scrub each pin bright using crocus cloth, steel wool or a fine wire brush, then reconnect.

Systems

• Electro-mechanical

Related tips

• EM game acts crazy after reconnecting head plugs

Source: Pinball Machine Care & Maintenance, Bernard B. Kamoroff (Bell Springs Pinball Alley)