Project P.I.T.T. has three fuses in the accepted puzzle evidence. Gameplay places them around the window area, a ceiling light, and the central slanted beam, and all three go into the Fuse Box before the 200 kg hidden chain continues. The camera or brief upper-access restriction affects the route, but movement paths and visual hints can differ by version.
Handle the camera restriction first
Accepted achievement footage shows the upper or mezzanine route interacting with a camera and a short access restriction. Destroying or disabling the relevant camera is one documented way to make the search manageable, while a community route also mentions reaching or knocking down a high fuse. Treat these as demonstrated methods, not proof that every build allows only one approach.
Search the three verified areas
The clearest footage identifies fuse locations around the window, the ceiling light, and the central slanted beam. Look for the current build's added visual hints before relying on an exact jump sequence from an older recording. When you find a fuse, move it somewhere safe or install it promptly so that a loose physics object is not lost among factory products.
Install every fuse in the Fuse Box
The puzzle requires all three fuses, not merely reaching the upper walkway. Carry each fuse to the Fuse Box and confirm that it occupies a slot before searching for the next progression change. If the chain does not advance, recount the filled slots and check that one fuse is not resting near the box without being registered.
Continue to the 200 kg chain
Guide, community, and gameplay sources connect the completed fuse puzzle to the later 0/200 kg platform route. Once all three are installed, inspect the newly available access and use the dedicated 200 kg page for the mass requirement. Do not confuse opening that chain with completing the secret ending itself, because more hidden steps remain.
Adapt to version changes
The developer acknowledged the fuse puzzle and added more visual guidance, which means older videos may look less clear or route differently than the current game. Use the broad locations and three-slot acceptance as the stable facts, then follow present-day lighting, markers, and collision behavior. If a fuse is absent from a documented spot, confirm the version and nearby visual clues before declaring the puzzle broken.
Sources used for this answer
These links are the accepted evidence set for this page. Player methods are kept separate from official or developer statements, and unsupported details stay marked 待确认.