TARDIS power room

From Tardis Wiki, the free Doctor Who reference

The TARDIS power rooms were a series of fifteen interconnected rooms located deep within the heart of the Doctor's TARDIS, forming the nerve centre of the time machine. Located in the rooms were the regulators and engines which powered the TARDIS, keeping it running. This included lighting, heat, life support, navigation, memory banks, and the drive mechanisms. Throughout the room were old leatherbound technical manuals.

When attempting to diagnose the problem with the TARDIS following its dematerialisation from Skaro, the First Doctor and Ian Chesterton visited the TARDIS engine and power rooms. The pair found that the systems had completely stopped working, but could find no obvious fault. (PROSE: The Edge of Destruction)

The Second Doctor once retreated to the power room after using the emergency unit. Located just off the console room, it was key to fixing the TARDIS after the ship popped out of reality. Both Jamie and Zoe spent some time inside the room talking to the Doctor. (TV: The Mind Robber)