Halo Alpha
Halo Alpha


John-117 in a Shield Tester on the Pillar of Autumn.

The Shield Tester is a piece of machinery in use by the UNSC engineers to bring online inactive MJOLNIR armor energy shielding.


It appears in Halo: Combat Evolved and Halo 2, in the levels Pillar of Autumn and The Armory, respectively. Both times, it is used to bring online the MJOLNIR energy shields,[1] although its primary purpose seems to be testing the shields in Halo 2.


First mentioned in the Halo: The Fall of Reach novel, during the MJOLNIR Mark V's first mission, this device charged the armor's shield before they were activated by John-117, like a battery.[2] In Halo: Combat Evolved, the tester makes the same noise as a Plasma Pistol overcharge impact, possibly hinting that they were made using scavenged Covenant technology.

It is unknown why the shields need an initial charging. Cryostasis may be a logical explanation for Halo: Combat Evolved, but the MJOLNIR Mark VI in Halo 2 had no such explanation. It is possible that the fusion power cell needed to reach a certain internal temperature to begin it's reaction and the initial charging gives it the energy to do so, or the new suit still had to be started up fully.


  • The UNSC Pillar of Autumn's tester has the same noise as an overcharged Plasma Pistol. This could be due to time constraints and a lack of a custom sound for the tester.
  • It is possible to be standing out of the shield tester area in Halo: Combat Evolved and in Halo 2. However, you won't be able to move while the shield tester is active.



  1. Halo: Combat Evolved level, Pillar of Autumn: Thom Shephard: "Okay, bring his energy shields online please."
  2. Halo: The Fall of Reach, page 236