#touch-id #apple #magic-keyboard #mac #3d-printing #teardown #mod # Overview Harvest the Touch ID sensor, logic board and charge port out of an Apple Magic Keyboard with Touch ID, and re-house them in a 3D printed box that sits next to whatever keyboard you actually want to use. Touch ID is only sold inside a Magic Keyboard — there is no standalone part — so the donor keyboard is destroyed in the process [P1 1:07](https://youtu.be/hz9Ek6fxX48?t=67). Two builds are covered here: SnazzyLabs' original **Standalone Touch ID Module** (3 variants, glue + heat-set inserts, non-clickable) and Calvin's **Clickable Touch ID Box** remix (TKL wired only, no glue, retains the physical click). The teardown is identical for both; only the case hardware differs. Apple silicon is required — Touch ID does not function on Intel Macs, which lack the Secure Enclave the external sensor authenticates against. The keyboard still works as a plain Bluetooth keyboard on Intel. Neither video says this; it comes from [Apple's tech specs](https://support.apple.com/en-us/121954) ("Mac with Apple silicon") and [9to5Mac's PSA](https://9to5mac.com/2021/08/03/magic-keyboard-with-touch-id/). # Resources ## Models - [Standalone Touch ID Module for Mac — SnazzyLabs (Printables 320000)](https://www.printables.com/model/320000-standalone-touch-id-module-for-mac) — 3 variants, 23 files - [Clickable Touch ID Box, TKL board, wired — Calvin (Printables 355924)](https://www.printables.com/model/355924-clickable-touch-id-box-tkl-board-wired) — remix of the above, 7 files, [editable on Tinkercad](https://www.tinkercad.com/things/20VXvaGcfWs-touch-id-box) - [Touch ID Box with Button Press — GLOUPY (Printables 349777)](https://www.printables.com/model/349777-touch-id-box-with-button-press) — the clickiness Calvin's remix was inspired by - [8BitDo Keyboard + A3119 Magic Keyboard Touch ID — MakerWorld](https://makerworld.com/en/models/3000285-8bitdo-keyboard-a3119-magic-keyboard-touch-id) — the only USB-C-era design found; embeds into an 8BitDo keyboard rather than a standalone box ## Guides and video - [KhaosT disassembly gist](https://gist.github.com/KhaosT/1406a6b6bea38f59e059c2afcb39d545) — the written teardown both model authors point at - [[Snazzy Labs Touch ID Module Transcript]] — P1, full auto-caption transcript - [[Level 2 Jeff Touch ID Box Transcript]] — P2, full auto-caption transcript - [Six Colors: Touch ID on a Mac desktop, deconstructed](https://sixcolors.com/post/2022/07/touch-id-on-a-mac-desktop-deconstructed/) — the velcro-under-the-desk + Karabiner approach this mod replaces # Donor Keyboard Selection ## Every Magic Keyboard with Touch ID ever made | Keyboard | Model no. | Board ID | Layout | Port | Introduced | Colors | Usable for this mod? | |---|---|---|---|---|---|---|---| | Magic Keyboard with Touch ID | **A2449** | A222AP | TKL / compact | Lightning | 2021-05-21 (iMac colors), 2021-08-03 (standalone) | Silver, White, Blue, Green, Orange, Pink, Purple, Yellow | ✅ **Best target.** Fits 320000 TKL wired + TKL wireless, and 355924 | | Magic Keyboard with Touch ID and Numeric Keypad | **A2520** | A223AP | Full-size, 109-key | Lightning | 2021-05-21, White 2021-08-03, Black 2022-03-08 | + Black (Mac Studio era) | ⚠️ 320000 full-size variant only. Board is too long for 355924 | | Magic Keyboard with Touch ID (USB-C) | **A3118** | A282AP | TKL / compact | USB-C | 2024-10-30 (White), 2024-11-08 (colors) | White, Silver, Blue, Green, Orange, Pink, Purple, Yellow | ❌ No case exists. Different board + USB-C port | | Magic Keyboard with Touch ID and Numeric Keypad (USB-C) | **A3119** | A284AP | Full-size, 109-key | USB-C | 2024-10-30 (White, Black), 2024-11-08 (colors) | + Black | ❌ Not for either linked model. Only the 8BitDo MakerWorld design | Model numbers and colors from [AppleDB](https://appledb.dev/device-selection/Keyboard.html); tech specs for the USB-C pair from Apple ([TKL](https://support.apple.com/en-us/121954), [numpad](https://support.apple.com/en-us/121953)). ## Decoys — do not buy these | Model no. | What it actually is | Why it's a trap | |---|---|---| | **A2450** | Magic Keyboard (2nd generation) — **no Touch ID** | Same 2021 launch, same colors, nearly identical to A2449. Shipped with the base 24" iMac. Countless eBay titles read "A2449 A2450 Touch ID" and lump them together | | A1644 | Magic Keyboard (1st gen), 2015 | No Touch ID | | A1843 | Magic Keyboard with Numeric Keypad, 2017 | No Touch ID | | — | "Shell only / missing internals" listings | The aluminium top case is worthless here — you need the board and sensor | ## eBay part numbers to search | Donor | Retail SKU (US English) | Apple service part | Other IDs seen | |---|---|---|---| | A2449 silver/white | MK293LL/A | 661-02159 | EMC 3579 | | A2449 iMac colors | — | 661-04378 (blue), 661-04380 (pink), 661-04385 (orange) | | | A2520 silver/white | MK2C3LL/A | — | | | A2520 black keys | MMMR3LL/A | — | | | A3118 USB-C white | MXCK3LL/A | — | | | A3119 USB-C white / black | MJM64LL/A / MJM74LL/A | — | | ==Service part numbers 661-04378/04380/04385 came from a used-parts reseller listing, not Apple — treat as indicative.== ## What it costs today (eBay active listings, 2026-09-09) | Condition | A2449 (TKL) | A2520 (numpad) | |---|---|---| | Working, used | $59–$100, clustered $70–$90 | $50–$100, clustered $75–$95 | | New / OEM sealed | $79–$100 | ~$100 | | Parts only / untested | $10 (auction) – $79 | $43 (no power) – $60 (broken) | | Empty shell or box only | $8–$20 — **useless** | $8–$20 — **useless** | SnazzyLabs paid $100 on Craigslist, 50% off retail, for a keyboard that came with an iMac [P1 1:07](https://youtu.be/hz9Ek6fxX48?t=67). Jeff frames the whole project as destroying a $100 keyboard [P2 6:29](https://youtu.be/tzB6m2VTxAg?t=389). Buying strategy: the ideal donor is a **cosmetically wrecked but electrically live** board — soda spill, jammed or missing keys, bent chassis — because you only need the board, the sensor and the port. On the Printables page SnazzyLabs suggests exactly that: *"use a board you find on eBay that's got soda spilled on it or crumbs jamming certain keys for a good price."* "Parts only / untested" is the right filter, but read the description: a listing that says *no power* or *Touch ID not recognized* is a coin flip, and one that says *shell only* is a guaranteed loss. Expect roughly **$45–$80** for a viable donor. The TKL (A2449) is the cheaper target on today's listings, and SnazzyLabs expects it to be the more common one on the used market, because it's what shipped free with the 24" iMac while the numpad version was a paid upgrade — his words, hedged as a prediction rather than a fact [P1 14:38](https://youtu.be/hz9Ek6fxX48?t=878). # BOM ## Donor parts (harvested) | Part | 320000 wired TKL | 320000 wireless TKL | 320000 full-size | 355924 clickable | |---|---|---|---|---| | Logic board | ✅ | ✅ | ✅ | ✅ | | Touch ID button + flex cable (keycap removed) | ✅ | ✅ | ✅ | ✅ | | Lightning port + flex | ✅ | ✅ | ✅ | ✅ | | Battery (793 mAh) | ❌ omit | ✅ | ✅ | ❌ omit | | Touch ID spring plate | — | — | — | ✅ | | 4× screws holding spring plate to button | — | — | — | ✅ reuse | ## Purchased hardware | Item | 320000 | 355924 | Notes | |---|---|---|---| | Donor Magic Keyboard w/ Touch ID (A2449 or A2520) | 1 | 1 (A2449 only) | $45–$80 used, see above | | M2×2–4 mm brass heat-set inserts | ✅ | — | Printables assembly tip; ==count not stated, likely 2 for the board plateaus== | | M2×4 mm machine screws | ✅ | — | Printables assembly tip. In the video he says only "M2 machine screws", no length [P1 12:24](https://youtu.be/hz9Ek6fxX48?t=744) | | M1.2×4 mm screws | — | 11× | Per Calvin's parts list: 2 Lightning port, 2 board, 7 button plate | | M1.2 hex nuts | — | 2× | Per Calvin's parts list; Lightning port only | | Rubber feet / bumper pads | optional | 4× optional | Per Calvin's parts list; Jeff adds them so it doesn't slide [P2 5:57](https://youtu.be/tzB6m2VTxAg?t=357) | | Electrical tape | — | optional | Per Calvin's parts list; insulates metal near the board | | Glue | ✅ | ❌ none needed | SnazzyLabs glues the bare sensor in place; ==type not specified== [P1 14:05](https://youtu.be/hz9Ek6fxX48?t=845) | | Filament, PLA or PETG | ~small | ~small | Not load- or heat-bearing, print in anything [P1 15:11](https://youtu.be/hz9Ek6fxX48?t=911) | Screw and nut counts come from Calvin's Printables material list, not from either video. Jeff's kits were generic Amazon assortments (M1/M1.2/M1.4/M1.6 pan-head stainless, 140 pc hex nut kit) — a few dollars each, and you'll want the whole assortment anyway. ## Tools | Tool | Needed for | Notes | |---|---|---| | Heat source | Both | The back panel is adhesive-only, no screws [P1 2:13](https://youtu.be/hz9Ek6fxX48?t=133). Jeff had no iOpener and leaned the keyboard on a space heater [P2 0:32](https://youtu.be/tzB6m2VTxAg?t=32); Calvin used a heat gun, and a commenter on his page suggests the printer's heated bed | | Spudgers, plastic + thin | Both | For the back cover and the ZIF connectors | | Fine curved-tip tweezers | Both | Jeff: *probably* the most important tool for the project outside a small screwdriver set [P2 2:42](https://youtu.be/tzB6m2VTxAg?t=162) | | Precision screwdriver set | Both | iFixit Mako or similar; the logic board screws are a *different* head from the back-plate screws [P2 2:09](https://youtu.be/tzB6m2VTxAg?t=129) | | T3 Torx driver | Both | 4× T3 screws hold the Touch ID sensor to its plate [P1 5:44](https://youtu.be/hz9Ek6fxX48?t=344) | | Soldering iron | 320000 | Heat-set inserts and the two Lightning-port plastic welds [P1 12:57](https://youtu.be/hz9Ek6fxX48?t=777) | | Digital calipers | Optional | Only if you're re-modeling | | 3D printer | Both | Or a print service [P1 15:46](https://youtu.be/hz9Ek6fxX48?t=946) | | Fine file or sandpaper | 355924 | Calvin: file down the raised center point on the C plate if it doesn't click, and he lightly sands the box and back plate top surfaces with 320 grit for finish. Jeff skipped sanding and reprinted instead [P2 4:19](https://youtu.be/tzB6m2VTxAg?t=259) | # Design ## The two cases compared | | 320000 — SnazzyLabs | 355924 — Calvin | |---|---|---| | Variants | TKL wired, TKL wireless, full-size (one model covers both wired/wireless) [P1 14:38](https://youtu.be/hz9Ek6fxX48?t=878) | TKL wired only | | Clickable | No — abandoned deliberately [P1 13:31](https://youtu.be/hz9Ek6fxX48?t=811) | Yes, the point of the remix | | Touch ID centering | Off-center by a few mm on the wired TKL | Centered | | Glue | Sensor glued in [P1 14:05](https://youtu.be/hz9Ek6fxX48?t=845) | None | | Heat-set inserts | M2 brass | None | | Supports | Yes | None | | Board hole drilling | May need widening | None | | Lightning port retention | Two melted plastic welds [P1 12:57](https://youtu.be/hz9Ek6fxX48?t=777) | 2× M1.2 screws + nuts | | Parts to print | 2 per variant (box + slide-on lid) | 4 (box, lid, C plate, back plate) | | Print profile | 0.20 mm layer, 0.40 mm nozzle, PLA or PETG | 0.20 mm QUALITY; **C plate at 0.10 mm DETAIL**; PETG, 100% infill, no supports | | Difficulty | Soldering iron work, more fiddly | More screws, but no melting or gluing | The 320000 listing quotes 33 h 17 m and 388 g — that's the aggregate across all 14 print files it contains (23 files total including the PDF and extras). You print one variant, so a fraction of that. ## Why SnazzyLabs dropped the click His original model had a cross/tee to retain the original keycap's click, and he abandoned it: he couldn't get a stable, replicable, nice-feeling key press, and concluded the button does nothing you can't do from the mouse or keyboard anyway [P1 13:31](https://youtu.be/hz9Ek6fxX48?t=811). Calvin's remix is the answer to that, and it does mean the physical click still matters for a couple of things Jeff names — booting the Mac from the module, and logging out [P2 4:19](https://youtu.be/tzB6m2VTxAg?t=259). ## Wired vs wireless The wired build omits the battery entirely, which is what makes the TKL wired case the smallest of the three [P1 14:05](https://youtu.be/hz9Ek6fxX48?t=845). You then run a Lightning cable to the Mac permanently. The wireless build keeps the 793 mAh battery [P1 3:53](https://youtu.be/hz9Ek6fxX48?t=233), at the cost of a much longer box. Jeff's take: getting that battery off without bending it into a fire hazard is its own gamble [P2 3:46](https://youtu.be/tzB6m2VTxAg?t=226). For the full-size 109-key donor there's only one case, because that board is longer than the battery anyway [P1 14:38](https://youtu.be/hz9Ek6fxX48?t=878). # Teardown Notes ## Getting in - No screws under the back panel — it's adhesive all the way around, and the aluminium will bow as it heats [P1 2:13](https://youtu.be/hz9Ek6fxX48?t=133) - Budget 5–10 minutes of prying just to get the back ready to peel; it will never go back together like new [P2 1:04](https://youtu.be/tzB6m2VTxAg?t=64) - Adhesive is under the battery but not on top of it [P2 1:04](https://youtu.be/tzB6m2VTxAg?t=64) - ~20 tiny screws hold the black plastic cover plate [P2 1:36](https://youtu.be/tzB6m2VTxAg?t=96) - Residual adhesive still wedges the cover plate in at the corners; be careful here if you ever want to reassemble it [P2 1:36](https://youtu.be/tzB6m2VTxAg?t=96) ## Connectors Three connectors on the logic board plus the wide keyboard-matrix ribbon [P1 5:10](https://youtu.be/hz9Ek6fxX48?t=310): 1. Touch ID sensor (ZIF, on the back of the board) 2. Battery 3. Lightning port 4. Wide connector across the top → keyboard matrix. Flip the flap **and** peel the thin adhesive tape holding the cable [P2 2:09](https://youtu.be/tzB6m2VTxAg?t=129) ## The Touch ID sensor - Held by 4× T3 screws around its perimeter; the whole key fascia can be removed too [P1 5:44](https://youtu.be/hz9Ek6fxX48?t=344) - With the keycap off, the bare sensor reads a fingerprint on its top face, and the little button on the back registers a press whenever something depresses it [P1 6:18](https://youtu.be/hz9Ek6fxX48?t=378) - There's a thin sticker over the Touch ID wire connector and it's fragile on a long cable — go slow [P2 2:42](https://youtu.be/tzB6m2VTxAg?t=162) - ==Jeff believes the Touch ID sensor is hardware-paired to its logic board== — if the flex tears, the whole donor is scrap. He was 50/50 on ripping his and has torn these before. A little heat on the flex might help next time [P2 3:46](https://youtu.be/tzB6m2VTxAg?t=226) ## It works without the keyboard SnazzyLabs hadn't tested this before gutting his. Plugged in bare, macOS reports "keyboard battery level 0%", but fingerprint enrollment completes normally and the lock screen unlocks on touch alone — no button press needed [P1 7:58](https://youtu.be/hz9Ek6fxX48?t=478) [P1 8:31](https://youtu.be/hz9Ek6fxX48?t=511). # Recommendations - Buy a cosmetically destroyed donor, not a nice one. Spilled-on and crumb-jammed boards are exactly as good electrically. - Verify the listing says **A2449** or **A2520**, never A2450, and confirm the photo shows the round Touch ID key at the top right. - Buy the TKL (A2449) unless you specifically want the full-size case — it's cheaper, more common, and the only donor the clickable remix accepts. - Skip USB-C donors (A3118/A3119) entirely for these two models. They're newer, pricier, and no standalone case exists. - Print the 355924 C plate at 0.10 mm and test-fit the button *before* assembly; the click bump height is the make-or-break dimension. Sand the raised center point down if it binds [P2 4:19](https://youtu.be/tzB6m2VTxAg?t=259). - Connect the ribbon cables before screwing the logic board down — reaching the connectors afterward is impractical [P2 5:24](https://youtu.be/tzB6m2VTxAg?t=324). - The Lightning port screws + nuts are the worst step. Balance the nut on the screw through the port and start the thread with a finger on top; expect two or three attempts [P2 5:57](https://youtu.be/tzB6m2VTxAg?t=357). - Print material genuinely doesn't matter — no heat, UV, stress or torsion on this part [P1 15:11](https://youtu.be/hz9Ek6fxX48?t=911). # TODO - ==Decide: 320000 wired TKL (glue + inserts, simpler print) vs 355924 clickable (more screws, better result)== - ==Source donor — set eBay saved search for "A2449 parts only" and "magic keyboard touch id not working", target under $60== - ==Confirm M2 insert/screw count for 320000 once the STLs are open in the slicer== - ==Verify MMMR3LL/A is the black-keys A2520 SKU (seen on a broken-unit listing, not on an Apple page)== - ==Check whether the clickable back plate needs a re-print or just sanding on the printer being used== # References - [[Snazzy Labs Touch ID Module Transcript]] - [[Level 2 Jeff Touch ID Box Transcript]]