Hyperdrivet var inte trasigt, det var skadat . Det hade tillräckligt (sätt in teknobabble här) för att få dem till ett närliggande system.
Detta förklaras i filmens skript
RIC OLIE : There's not enough power to get us to Coruscant...the hyperdrive is leaking.
QUI-GON : We'll have to land somewhere to refuel and repair the ship.
och mer i detalj i novelleringen
When they were well away from any Trade Federation presence, Ric Olié made a thorough check of the controls, assessing their damage, trying to determine what was needed. Obi-Wan sat next to him in the copilot’s seat, lending help. Qui-Gon and Captain Panaka stood behind them, awaiting their report. The Queen and the rest of the Naboo had been secured in other chambers. Ric Olié shook his head doubtfully. “We can’t go far. The hyperdrive is leaking.”
Qui-Gon Jinn nodded. “We’ll have to land somewhere to make repairs to the ship. What’s out there?”
Ric Olié punched in a star chart, and they hunched over the monitor, studying it.
“Here, Master,” Obi-Wan said, his sharp eyes picking out the only choice that made any sense. “Tatooine. It’s small, poor, and out of the way. It attracts little attention. The Trade Federation has no presence there.”[later]
The hyperdrive generator had failed completely as they landed. It’s a good thing it didn’t give out between star systems, Qui-Gon thought, looking down at the mess Obi-Wan had just hauled out of the drive compartment. Perhaps that was what had made him so uneasy, these last few hours … but no, he could still feel disquiet in the Force.