Show HN: Reverse-Engineering a Switch Lite with 1,917 wires
Reverse‑engineering a 10‑layer Nintendo Switch Lite motherboard by hand-soldering 1,917 wires has sparked wider interest in how to systematically extract netlists and board views from modern high‑density PCBs. Commenters explore alternative approaches such as flying‑probe rigs built from 3D printer hardware, destructive “sand‑and‑scan” imaging, and X‑ray/CT techniques, noting that industrial and Chinese services already automate much of this for a fee. Many see detailed board data as valuable for right‑to‑repair, diagnostics, and niche hardware projects, but question how such labor‑intensive methods can scale and how an open, affordable toolchain might be funded.
Overall reaction
- Strong admiration for the ingenuity, manual skill, and persistence in wiring ~2,000 connections.
- Multiple commenters note the method is technically clever but question its practicality and scalability.
Alternative technical approaches
Flying probe / 3D printer platforms
- Many suggest adapting cheap 3D-printer motion systems into flying-probe testers.
- Ideas include dual‑sided probing, automated re‑probing for bad contacts, and capacitance sensing to verify hits.
Scan–sand–scan and imaging
- Destructive sanding between high‑res scans is seen as the most accurate for multilayer boards, capturing ground planes, guard traces, and microvias.
- Challenges: PCB warping, dust, need for precise flattening; mitigation via more frequent imaging and digital “flattening.”
- Some link this to medical CT‑style volume reconstruction and common computer‑vision tasks (alignment, blob detection, via detection).
X‑ray / CT
- Commercial CT-based netlist extraction exists but is proprietary and expensive.
- Anecdotes of sending boards out for CT and getting interactive 3D tools back.
- Interest in DIY or open‑source CT/X‑ray solutions, with examples of homebrew scanners using specimen X‑ray machines.
Bed‑of‑nails / mirrored PCBs
- Proposals for dense probe grids or custom mirrored breakout PCBs connected via anisotropic films, solder paste, or pogo pins.
- Others argue this doesn’t scale to modern fine‑pitch BGAs; a small board would need tens of thousands of contacts.
Automation of soldering
- Suggestions to treat this like a wire‑bonding problem: robotic soldering, laser soldering, or die‑bonder‑style machines to place and attach wires to 0.2 mm pads.
Netlists, utility, and limitations
- Netlists are useful for:
- Board‑level diagnostics and repairs, reducing e‑waste.
- Finding hidden signal access points for mods and hacks.
- Some argue partial/manual tracing (IC pinouts, obvious nets, probing key chips) is usually enough and far cheaper.
- Others counter that “80% complete” connectivity is often useless, especially with undocumented ICs and obscure signals.
Scalability and economics
- Multiple comments say this method is too labor‑intensive for broad use; hundreds of hours per board is unrealistic.
- Chinese PCB reverse‑engineering services are cited as cheap and highly automated (sand‑and‑scan plus software to derive netlists and even Gerbers).
- Some suggest the real value is in imaging tech, possibly as a mail‑in service, plus selling standardized extractor PCBs while open‑sourcing software.
Funding / project direction
- Ideas include crowdfunding or bounty‑style campaigns to fund reverse‑engineering specific high‑value boards (vintage computers, classic hi‑fi, game consoles).
- There is interest in an open‑source toolchain for image‑to‑CAD / boardview generation and web‑based viewers using tiled zoom (e.g., OpenSeadragon).
Miscellaneous technical points
- Crosstalk concerns are raised; author reports stable results at 20 kHz with repeated runs.
- Clarification that a “binned location” is just an indexed storage pocket so removed parts can be individually measured and referenced later.