ComputingYou will see this often
Keyboard
Also called USB keyboard, mechanical board.
A membrane keyboard is a cable and a case. A mechanical keyboard is a tray of real switches. Know which you have before you spend an hour.
A donor is the dead machine. The parts below are what is still worth removing from it. “Leave it” is a part that is physically in there and should stay in there: too dangerous, too worn, or only useful as part of a repair you are not doing.
A scrapped machine is a box of parts that failed at different times. The reason it was thrown out is often one bad piece. The motor, the cord, the supply, and the screws are frequently still good. This index says which is which.
Why it is in the trash while the parts are not
A dead controller, a spill, or a layout change. Spill damage that reached the switches is corrosion. A dead controller on a dry board leaves the switches healthy.
Before you open it
Do this while it is still unplugged, cool, and not leaking. Unplug. Tip out the crumbs. Spill damage smells like sugar.
Where the dead machine usually is
- Home office — In the house
- Office cleanout — Commercial
- Bulk trash day — Curb
Office keyboards are almost all membrane. Mechanical boards show up when a hobbyist upgrades.
How it comes apart
Membrane: the top clamshells. Do not expect switches. Mechanical: desolder or unclip depending on the plate. The diodes are on the board.
Tools: A spudger, Iron and pump for a mechanical board.
What to take
The table is the short version. The notes under it describe that part inside this machine, not only the general description.
| Part | Call | How many | How often | Where to look |
|---|---|---|---|---|
| Mechanical keyswitch | Prize | 60–100 | sometimes | Only on a mechanical board. |
| USB cable | Worth pulling | 1 | usually | Fixed or detachable. |
| Tactile switch | Leave it | many | always | Membrane boards. |
| Screws and standoffs | Bonus | several | usually | Case. |
| Enclosure | Bonus | 1 | sometimes | Aluminum cases on better boards. |
Prize
MX-style or similar, two pins.
Only on a mechanical board.
Desolder. Test each, because spills are uneven.
Excellent when dry.
Worth pulling
Detachable USB-C or mini-USB cables are the better prize.
Fixed or detachable.
Unplug a detachable one. A fixed cable is ordinary USB.
Good if it is not intermittent.
Bonus
Small Phillips, sometimes the only thing worth bagging.
Case.
Bag them.
Good.
A flat tray.
Aluminum cases on better boards.
Only if it is rigid.
Dented.
Leave it
A rubber dome over a plastic sheet. Not a salvage switch.
Membrane boards.
Do not harvest the membrane.
Worn.