The "K" key will activate the holobase overlay. This will highlight your machines and laser power beams so they show through terrain. The holobase can help you identify problems in your base, locate machinery through walls/floors, and serve as a poor man's waypoint system.
Anything that is red or flashing may possibly need attention. Conveyors that are backed up will show up red, as will ore extractors that have stopped working. Mynocks eating from conveyors will show as a red pulsing sphere when they take an item. Inactive Hiveminds are green blocks. The active hivemind will show an image of the hivemind. A red arrow is an entity, such as a slime, camobot, or wasp.
Pressing the "U" key while the holobase is active will switch to "Map Mode." This will give you a 3rd person schematic view of your base with all terrain removed.
Pressing the "Left Ctrl" key while the holobase is active will turn on "Tactical Mode" this will show spheres indicating the range of any turrets you have placed. Tactical Mode also works when the holobase is in Map Mode.
Ore Extractors with 'issues' flash red on the holobase.
OE Yellow = working Red/Blue Flashing = Out of Power Red/Cyan Flashing = Out of Storage Red/Black Flashing = Idle Red/Green Flashing = Drill Stuck