手伝ってくれるかい、この機械の作動の仕方が分からないんだ。

English Translation

Can you help me? I can’t make out how to start this machine.

作動 means “to operate” including starting and turning off the engine. It doesn’t necessarily means “to start”.
I guess the Japanese original translator mixed up 作動(さどう)with 起動(きどう). 起 of 起きる means “to wake up” or “to kick off”. So, 起動 is used when you start a machine. 起動ボタン means a “start button” on a machine or computer.