Fitting a new power cord, ideally three-prong

Steps

• Unplug the game and cut the old cord out.
• Identify the hot conductor: on the old cord it is the one with a moulded rib; on the new cord it is the ribbed (or black) conductor going to the wider plug blade.
• Connect the new hot conductor to the same lug the old ribbed conductor used, the one leading to the power switch if fitted.
• Connect the other conductor to the other lug.
• On a three-prong cord, bolt the green ground wire to the transformer's metal frame.
• Tie the new cord to the harness with nylon ties where the old one was.

A cheap 15 foot extension cord with its socket end cut off makes a suitable cord. Getting hot and neutral backwards won't stop the game but is less safe.

Unplug the game first: the power cord, fuse block and transformer primary carry 115 V line voltage.

Systems

• Electro-mechanical

Related tips

• New line cord trips the GFCI at once: cord conductors joined to the wrong game wires
• Add a power switch to an EM that has none
• High tap: a little more coil power from the transformer

Source: Repairing Electro-Mechanical (EM) Coin Operated Games to 1978, Part Two, Clay Harrell (pinrepair.com)