Large switch

Located in the very depths of Cybertron was a device created by the Quintessons during their rule over the Transformers... a device operated by a large switch.

The true details or capabilities of the device were not known except that it was linked to every Autobot and Decepticon to the point that, if switched off, the device would result in all the Transformers becoming inert.

The Transformers cartoon
The Quintessons used their new Decepticon allies to assault Cybertron while they secretly sent a commando team of Sharkticons into the depths of Cybertron to push the switch to the down position, which would have deactivated all the Transformers. The Sharkticons failed in their task because of Blitzwing and Rodimus Prime. However, the mad Galvatron thought that the switch was related to the Decepticon Matrix of Leadership, which was a Quintesson lie, and threw the switch himself. This stopped the Transformers war by stopping all the Transformers, leaving Cybertron back in the hands of the Quintessons. That is, until Spike Witwicky used Rodimus's gun to destroy the switch, which reactivated the Transformers again, leaving the ever-irrational and maniacal Galvatron really ticked off at the Quintessons....

Story of Binaltech
Battle-weary from fighting firstly Unicron, and then a full-strength Decepticon army returned from their protective sojourn in the Kronosphere, the Autobots enacted a desperate plan. Using information obtained from Ravage, they discovered the existence of a switch that would render all the Transformers inert. While it would mean the Autobots would cease to function, the fighting - and their losses - would stop, and their human allies might be able to restore them at some point. Mirage infiltrated the location of the switch and activated it. Across the universe, all the Transformers froze where they were..... except for those in Binaltech bodies. The Binaltech process underwent by numerous Autobots, including storage of their sparks in subspace, protected them from the switch's effects, resulting in their unexpected immediate victory over their foes, due to the significantly fewer Binaltech-upgraded Decepticons.

Transformers: Universe
The Quintessons used their new Decepticon allies to assault Cybertron while they secretly sent a commando team of Sharkticons into the depths of Cybertron to push the switch to the down position, which would have deactivated all the Transformers. The Sharkticons failed in their task because of Blitzwing and Rodimus Prime. However, the mad Galvatron thought that the switch was related to the Decepticon Matrix of Leadership, which was a Quintesson lie, and threw the switch himself. This stopped the Transformers war by stopping all the Transformers, leaving Cybertron back in the hands of the Quintessons. That is, until Kicker kicked the switch back on, which reactivated the Transformers again, leaving the ever-irrational and maniacal Galvatron really ticked off at the Quintessons.... Optimus used the Star Saber to destroy the switch.